Legal Week's recently published UK top 50 rankings revealed that the country's 50 largest firms brought in total turnover of £18.24bn during the last financial year, 5% up on 2014-15. However, it was a year characterised by much market uncertainty, with the impact of the Brexit referendum looming large.

Here, management figures at some of the UK's top law firms discuss the key trends from 2015-16, including consolidation, job cuts, artificial intelligence and profit per equity partner (PEP) – as well as the most pressing challenges for the year ahead.

Simon Levine, global co-CEO, DLA Piper

On 2015-16: "We are pretty pleased with our results. There will always be firms that are more profitable than us, it's a competition in a sense, but really you are trying to provide the right results for our partners. We are a very particular type of firm – it's hard to compare us to a firm that focuses just on corporate finance or just the US or the UK, as opposed to being a full-service commercial global law firm. When I look at our performance against other firms, it performs well – the important things are that our revenue is growing, our profits are growing and we have kept our costs under control; and we have continued to expand into new places and offer new services."

On Brexit: "Brexit has had an effect even on a global basis, not just in the UK or Europe. Anything that makes people hesitant about doing deals affects your business."

On the market: "What you are seeing is, slowly, a reshaping and restructuring of the global legal market. What we have been through over the past ten years and the economic downturn has slowed that process but we continue to see certain law firms making the break to become global full-service law firms – which some firms positively do not want to do because maybe their strategy is to be selective geographically or to specialise in a particular practice or sector – and many of those firms are doing well.

"But you also see firms caught in the middle. Imagine a cyclist competing at the Olympics – you have breakaway groups and then the peloton. In the legal industry, you have a breakaway of the big global firms and the other more boutique firms that have specialised, and others just undecided in the middle – those are the firms that will struggle.

"The question for those firms is: do they merge with a bigger firm and lose their identity, or try to retain their identity and form a bigger firm with another mid-size firm, which I think is massively difficult to do? Some will just break up – there are clearly firms out there that are struggling.

"In the UK, you will get some more consolidation at the lower end of the market. The firms you don't want to be are those with a small number of offices, or very committed to a particular practice, like real estate for example. Because if the real estate market goes down, you have a problem. Those are the people in the most trouble."

On PEP: "Equity spread and looking at PEP have become, since I started as a partner in 1997, completely meaningless. When I became a partner, the biggest firms had, say, around 80 partners, pretty much all on a lockstep, so PEP and equity spread mattered. Now there are very few pure lockstep firms – the partner agreements term people in all sorts of ways: members, salaried partners, junior equity partners. It's meaningless – there is no accurate way of comparing PEP and equity spreads because firms all have different structures." 

Andrew Ballheimer, managing partner, Allen & Overy

On 2015-16: "Our global M&A and disputes practices both boomed during the last financial year. M&A has been extremely busy in most developed markets but we have seen a slowdown in China-inbound work. The Middle East has been affected by the collapse in oil and gas prices. Generally, we saw a slowdown in the second quarter of the calendar year as a result of the uncertainty surrounding the Brexit vote."

On Brexit: "The Brexit vote, along with elections in continental Europe and the US, create uncertainty and we know this does affect business decisions. The drop in sterling's strength is likely to lead to a decent amount of opportunistic public M&A in the UK. I don't believe English law will diminish as the jurisdiction of choice for financings following the vote. It is still very much accepted as the market standard."

On technology: "In terms of technology that can be used to improve efficiency in processing, that's already here. We are able to leverage this capability for high volume work. In terms of artificial intelligence (AI), there's lots of talk about it but I think we need to look forward to the next five-year period to see real changes involving its applicability in a meaningful way."

Peter Hasson, chief executive, Clyde & Co

On Brexit: "The real danger is if firms spend their time navel-gazing for six months and not being prepared to commit to expansion or strategic plans, which could hamper them further down the track. Until it becomes clear how Brexit will work, there will be a degree of nervousness around.

"Those in the market who already saw merger as a solution to their challenges will no doubt think it is even more important to do that, but Brexit has probably has deterred some international firms from wanting to extend their footprint in the UK. When I talk to people in the US I often find they are much more worried about the impact of Brexit than is apparent in the UK market."

Matthew Layton, managing partner, Clifford Chance

On 2015-16: "Last year we saw revenue growth in all jurisdictions in local currency, as well a particularly strong performance in the US, where we grew revenue by 13%, and Asia-Pacific, where we've doubled revenue over the last eight years. Continental Europe also performed well. It was also a strong performance across all practice areas including litigation, real estate, M&A, capital markets and finance.

"This year, there are a number of important factors affecting our clients and particularly their appetite for transactional activity, including the lead-up to the referendum and the subsequent uncertainties around the timing and shape of Brexit, important elections in US, Germany and France, and slow global growth."

On Brexit: "In terms of Brexit, we have been very active on this subject for the past three years, working with trade bodies and supporting clients internationally as they develop their strategic plans. For us, this will continue to be a major theme."

Steve Immelt, chief executive, Hogan Lovells

On Brexit: "We all know Brexit had a dramatic impact on the UK deal market. It's hard to know what the post-Brexit environment will look like. We are seeing some resumption of transactional activity but I think people are now adjusting to the understanding that Brexit will have a dragging impact.

"The US market remains strong but is probably not as frothy as it was last year. We're seeing a good level of deal activity but the pipeline is not as full as it was a year ago. There is a lot of uncertainty around that did not exist a year ago, which has arisen out of Brexit and the US presidential election and that is having an impact on things."

On technology: "I think the reports of the death of the legal sector have been a bit premature – I don't see technology as fundamentally changing the sector. I think tech will affect the way people work, particularly anything involving an assessment of a large amount of data such as a diligence process or a document review project. Although it doesn't exist today, it is possible that AI will be brought in on things like legal research. However, I see these things as tools for lawyers to use rather than replacements."

On the market: "Given the flat level of demand for legal services, it is more important than ever for firms to be focused on what their strategy is. In a world of slow growth, that is the reality firms have to face. You can't stimulate demand that doesn't exist and if the macroeconomic picture isn't there, then the sector will continue to struggle. Even if Brexit had gone the other way, we still would have seen a challenging legal market over the next five years."

Steve Cooke, senior partner, Slaughter and May

On Brexit: "Deal activity may be affected by the uncertainty that is likely to prevail until the terms of Brexit become clearer but it is too early to form a definitive view. However, we continue to be involved in some of the most interesting and high profile international transactions. There is also an encouraging amount of financing activity ongoing, as well as a significant amount of dispute resolution and investigations work."

Jeremy Hoyland, managing partner, Simmons & Simmons

On Brexit: "I don't think Brexit is helpful. But I don't think London will stop being a key financial centre or that UK-headquartered law firms are not going to have much to do. Corporate transactions remain pretty busy, particularly on the capital markets side. There's been a slowdown on the lending side but litigation continues apace and regulatory work has obviously increased.

"My personal bet is that our 2016-17 revenue is going to be negative but not hugely negative. I would be surprised if Brexit proves to be as massive an issue as the 2008 crisis.

"We are looking at business cases for London hires again in light of Brexit but we're not hunkering down and saying we're going to lock the doors. Our current view is that most practices outside the UK won't be impacted by Brexit."

Lisa Mayhew, managing partner, Berwin Leighton Paisner

On the market: "The legal sector continues to offer a lot of opportunities, both in key sectors and markets but also as a result of shifts in client demand, which are driving growth of 'enterprise' businesses such as Lawyers on Demand."

On 2015-16: "2015-16 was always going to be a different year, even putting Brexit to one side. European and Asian markets have slowed further and our clients are telling us that uncertainty is slowing their readiness to make big decisions. That said, Brexit is also throwing up opportunities for us and other law firms.

"The UK real estate market has slowed since the vote but there are already signs that it is recovering – we have worked on some high value deals and there are also some interesting opportunities in what is a reasonably healthy new business pipeline. Having said all of that, the summer break means it is hard to know whether the market will bounce back – so we won't really know until later in the year."

Ciaran Carvalho, senior partner, Nabarro

On the market: "We certainly haven't thought about redundancies or freezing pay; our business has held up. We have a diverse real estate client base, from institutional to private equity, and sterling has dropped in value so there are also opportunities.

"2016-17 will be more challenging because where there is uncertainty, people on the transactional side tend to think harder about things, so it is slower. However, the early signs are not that it will be dramatically different. Naturally we have to be cautious at a time like this, because no one knows how things will unfold. There will be a degree of caution rather than bravado, with people taking a little bit longer over decision making."

Sharon White, chief executive, Stephenson Harwood

On the market: "In the last five years we've increased our revenue by 44% and our PEP by more than 50%. 2015-16 was an exceptional year for the firm. To have built on that, with another record year, demonstrates the strength of the business.

"We continue with a 'business as usual' approach; we have a well hedged and diverse business and our balance sheet is healthy. Activity levels across the firm are good. We have a strong and diverse business, a broad, international client base and great people."

On Brexit: "The big issue remains what kind of relationship post-Brexit Britain will seek with the rest of the EU. Uncertainty fuels anxiety and no one should be fooled by the relatively quick recovery of the markets since the end of June. We won't know for some time what the vote to leave the EU means for the UK but I'm confident that London will continue to be a major financial and commercial centre. Similarly, the reasons why clients chose English law and the English courts remain unchanged."

Stephen Millar, UK managing partner, CMS

On 2015-16: "Our corporate group has had a particularly good year. We achieved double-digit growth globally in corporate and finance, up 14% and 12% respectively. The steep drop in oil prices, China's slowdown and of course Brexit have to be taken account of; however, while some market conditions have had an impact on the sector, opportunities are presented in others – such as the strengthening global economy." 

Mark Rigotti, joint CEO, Herbert Smith Freehills

On 2015-16: "For us, real estate was really strong on the transactional side across all sub-sectors and we found that the sort of firms we deal with in the real estate sector had similar experiences. We also did a lot of work in Africa, despite the impact of low oil prices and weak commodity prices. The other area that seems to be pretty hot as a whole is bribery and corruption, and regulatory investigations.

"Some capital markets particularly struggled pre-Brexit. Things that are very price dependent are very hard to predict. M&A was also affected by dips in confidence and we did see a bit of a stutter in the second half of the financial year leading up to the referendum."

On Brexit: "After the initial shock of the vote started to subside, a clearer picture began to come through, at least in the immediate term. As we now look at numbers, we see there has been more resilience in transactional activity than we might have expected. There is still uncertainty over whether some transactions will still complete. The other dimension of the post-Brexit environment is how it has affected currency. In our sector, we have to think about currency in terms of the impact on clients and also our own business. Everybody is still trying to work it out – it's a bit of an unfinished chapter in the post-Brexit book.

"I think in the future there will be some tests on Britain's attitudes to foreign investment. We may see more regionalism come in if borders become less porous. We're also thinking about how the US election may affect things. The other thing that could be a big game changer for law firms is the potential liberalisation in India. We're keeping a close eye on that market."

On technology: "We look at what technology means for our clients and how we need to change to serve them, as well as looking at what changes we can use in our own business. Over time, it will mean more automation in either back- or front-office functions. We're all still trying to work out how to apply AI to the legal sector too. The big strategic question is: how far ahead of the curve do you want to go and how much money are you willing to put into it?"

Charles Martin, senior partner, Macfarlanes

On 2015-16: "2015-16 was a pretty decent year given we maintained the revenue level of the previous year, which had been exceptional. Naturally the cost base was higher, so profitability suffered as expected."

On Brexit: "Our clients are unclear about how Brexit will affect them and their plans, and therefore it is hard to predict what the medium- and long-term impact will be on us as a firm. We expect the City to remain a pre-eminent global business centre."

On the market: "Firms that are looking to both grow revenue and increase profitability will find market conditions challenging. This feels like a year for listening carefully to clients and looking closely at efficiency and business mix. Few will perform very strongly in these conditions. For overseas clients, our sterling fees look better value than they did before. However, US firms that are prepared to pay dollar-equivalent salaries will attract some able lawyers. In reality, the pay differential has been there for some time and successful UK firms have a lot of attractive features for talented young lawyers looking to take a long-term view."

David Patient, managing partner, Travers Smith

On 2015-16: "We had a record year, largely due to the hard work of everybody at the firm and the groundwork laid over the last few years in terms of the investment we have made in our business. We have a well hedged business at the moment, so if one area is not performing quite so well, another one will be countering that. We dodged that Brexit bullet, particularly in the last quarter of the financial year when, I suspect, some other firms may have found trading conditions tough."

On Brexit: "Clearly the biggest risk to business at the moment is the impact of Brexit. I think that a lot of people, myself included, will have said that we were going along very nicely at a rate of knots. Suddenly, the referendum result comes along and it is a shock to the system. As it happens, we had a very busy summer. It is impossible to call the short-, medium- or longer-term effects of Brexit just yet and that's the biggest concern that law firm leaders will have.

"I am optimistic. I believe that English law will continue to be used in the future. Inevitably, we might see some impact on transactions but we are seeing a lot of interest from our foreign law firm network on behalf of clients looking at transactions in the UK."

On technology: "In my view, the three key issues in the legal sector are always technology, people and space – and they are intertwined. How will we use technology to make our business more efficient going forward? Will new technology have an impact on the number of people we employ? Will we need as much space going forward as people take advantage of new technology to work remotely and on the move?

"We are looking at and trialling all kinds of different AI systems and generally exploring what the right IT infrastructure is for our law firm over the next few years."

Stephan Eilers, co-managing partner, Freshfields Bruckhaus Deringer

On 2015-16: "We are really happy with the past financial year. Our revenue is up by 6.6%, net income is up by 7.5%, and PEP is up by 7.6%, which is very respectable.

"There are four factors that have impacted our results. Firstly, we have invested in the US and it has paid off. We have a very respectable corporate and capital markets practice in the US, which is closely tied to the corporate and capital markets practices that we have on the continent and in London. Secondly, we have benefited from having a good team in China and Mandarin-speaking partners on the ground in Germany, as we have seen a lot of Chinese investment into Germany where Chinese companies have been buying German mittelstadts for significant sums of money. Thirdly, we have seen a steadily increasing presence of regulatory work, antitrust work and cartel work. Finally, we opened an office in Manchester in order to drive greater efficiency."

On Brexit: "We think the firm is very well positioned. We have the strongest German practice, so if Frankfurt were to become stronger as a result of Brexit, we would profit from it. If there was a greater need for support around EU negotiations, we have an EU practice that is well positioned. It's a trend that looks worrying on the face of it but which ultimately plays to our strengths. We do not see Brexit as a fundamental crisis for our business. Instead, we see this as a positive challenge and from what we have seen over the past three months, there has not been a lot of concern regarding transactions in Europe and the US. The financial crisis of 2008-09 was a very successful period of change for the firm as well."

On the US: "A big investment for the firm over the past couple of years has been in the lateral hiring of US partners, who represent the very best of the transactional and capital markets space in the US. Our New York and Washington offices have grown significantly and now count 37 partners and around 200 lawyers between them. That is a real operation and our growth, which will continue, allows us to compete with other firms."

On the year ahead: "The rising number of antitrust liability claims made by people damaged by cartels is a huge development in the EU and plays to some of our strengths. This will spark a lot of litigation around antitrust issues.

"It could be a difficult year for mid-sized firms that are UK-focused and do not have an international footprint, particularly given the upcoming elections in the US and continental Europe. The challenge and uncertainty is not such a bad thing for lawyers but if there is one group at risk, it's UK-focused firms with a high cost base."

Andrew Saul, senior partner, Osborne Clarke

On the firm's results: "The biggest single factor was the delivery of our sector strategy. It has really come good and it's taken us up the food chain in terms of quality of work."

On the market: "Overall, it seems to be a lower growth market. Taking into account our full-year performance in 2015-16, the year was busy but we sensed that for some firms things were cooling off a bit in the final quarter."

On Brexit: "Our view is that it is still incredibly early days for business planning. We've focused on staying close to clients and understanding what impact the referendum is having on them. While there was a period of uncertainty immediately after the vote, the hard data is showing a rosier picture. I think it's important to avoid hasty decisions. We are very much committed to having a strong European platform, so nothing has changed there.

"Although there is a degree of uncertainty in the current financial environment, we are also seeing overseas clients and investors looking to benefit from currency movements, so that's an interesting macroeconomic development."

On technology: "More efficient and tech-led delivery of services is going to be an increasingly important factor. We have a dedicated partner, Dan Wright, whose responsibility is developing new ways of delivering services and creating client services on a bespoke basis. So yes, we are looking very closely at technology and innovation."

John Cleland, managing partner, Pinsent Masons

On 2015-16: "It has been a year where we have really turned up the dial on investment. It would be hard to think of a period in the firm's history when it has done so much in one year – we opened offices in Sydney, Melbourne and Duesseldorf; took a majority stake in Cerico, our online compliance solutions business; and brought in 23 lateral hires across our core sectors. All that plus a 5.5% increase in turnover. To be an international market leader in our global sectors we need to invest, and I think it's a pretty good achievement to make that unprecedented level of investment without diminishing profit."

On Brexit: "It's too early to be able to understand exactly what the consequences of Brexit will be. Naturally, certain areas of our business experienced some knock-on effects in the immediate aftermath of the Brexit vote, although it is striking that two of the largest deals we have completed this year signed within a couple of weeks of Brexit."

On consolidation: "There is certainly still consolidation to happen in the market but whether that will be among firms below the top eight, in an attempt to get into the club, is the question. Those firms are strong and are benefiting from the global reach that they have, but it will be challenging to push further up the ranks on the basis of organic growth alone."