Freshfields Bruckhaus Deringer, Skadden Arps Slate Meagher & Flom and DLA Piper have topped the global and European league tables over the first three quarters of 2015, as global deal activity slowed to its lowest quarterly level in two and a half years, data from Mergermarket reveals.

Skadden topped the global value ranking, with roles on $553bn of deals in the first three quarters of 2015, while DLA Piper topped the global and European volume rankings with roles on 279 deals globally and 156 in Europe.

Freshfields advised on the most European and UK deals by value and the most UK deals by volume.

The figures show there were 3,590 deals announced across the globe during the third quarter of 2015, 15% fewer than in Q2, when 4,231 were announced.

It is the first time a quarterly global deal count has fallen below 3,600 since the second quarter of 2013, when 3,336 deals were announced globally.

Global deal value fell less steeply to $1,024bn (£675bn), just 4% down from $1,064bn (£701bn). It is still only the second time since 2007 that the quarterly value of deals has surpassed $1trn (£659bn).

Richard Browne, head of UK corporate at Allen & Overy (A&O), says the data shows large strategic deals are dominating the global market. He adds: "We operate in a particular section of the market, predominately working on bigger deals, so I would say that volumes feel decent but that might not be the feeling for law firms that focus on different sections of the market.

"The reason we're seeing strong levels at the top end is that those are deals people have wanted to do for a while. So for firms like us it feels like the volumes are good."

The fall in both the global volume and value of deals in Q3 was also reflected in the European deal data, where Q3 was the weakest quarter so far in 2015 by both deal count and value. Deal count for the region was 1,332, its lowest level since the third quarter of 2012 when 1,269 deals were announced. Total deal value was $181bn (£119bn) compared to Q2′s $288.2bn (£190bn).

Mike Flockhart, a London-based corporate partner at Herbert Smith Freehills, which ranked 18 in Europe by deal volume, says: "The European market has been affected by the problems in Greece and broader geopolitical issues, but there are still a lot of drivers of corporate activity and the pipeline looks strong. There's been a lot of Asian investment in UK commercial property, for example."

However, Simon Beddow, global co-head of Ashurst's corporate practice, says the summer of 2015 has been "probably the busiest since the global financial crisis". Ashurst ranked 13 in Europe by value and 19 by volume.

Beddow adds: "During the last quarter of 2014 things slowed down, as did the first quarter of 2015 before the UK general election. There has been a knock on effect – that last and first quarter have affected this year's Q3."

Mergermarket's figures and rankings are based on announced deals rather than those that have completed. Andy Ryde, head of corporate at Slaughter and May, says this may lead to false impressions that firms were less busy in Q3, when deal volumes fell, than the first half of the year.

He says: "There are so many deals you work on that never see light the of day or they go on pause and come back months later. There was a sense of things going on pause a bit in Q1 – that may have been people waiting for the election outcome, Eurozone instability… there were a few factors at play that were causing people to pause. It was really May onwards we saw quite a few of those deals coming back and intensifying."

Matthew Middleditch, head of corporate at Linklaters, adds that there has been an increasing tendency for clients to cancel deals, albeit often for sound commercial reasons. "There's a greater willingness than in the past to stop deals… people seem more willing to say that it's not the right thing to do," he says.

Sector trends

Globally the financial services sector has so far grown the most in the first three quarters of the year, compared with last year.

Global activity in the financial services sector between Q1 and Q3 was up by 112% this year compared to 2014. During the first three quarters of 2015 $357bn (£235bn) of deals were announced, compared with $169bn (£111bn) of deals over the same period of 2014.

Beddow expects this sector trend to continue. He says: "I think we'll continue to see banking sector activity grow as there are a lot of ringfencing initiatives and restructuring of banks, and more companies in the financial services sector strengthening their balance sheets."

In Europe the figures show it is the technology and the energy, mining and utilities sectors that are outpacing growth in other sectors this year. The value of deals in the technology sector nearly doubled from to $49.7bn (£32.8bn) between Q1 and Q3 2015 up from $25.6bn (£16.9bn) over the same period of 2015.

Meanwhile, the energy, mining and utilities sector grew 80% to $115.2bn (£75.8bn), up from $64bn (£42.2bn).

Flockhart (pictured) believes the technology sector's growth is due to globalisation. He says: "Some sectors in particular are still doing well. Technology is an example of this. It's been a strong sector for some time, but I think one of the main drivers has been the globalisation of tech businesses.

"Originally you had Silicon Valley just leading the way, but now other tech markets are developing and are creating attractive acquisition targets for larger companies looking to diversify their platforms. London's Silicon Roundabout and the strong Scandinavian and German markets are examples of this."

Despite a dip in activity globally and in Europe in Q3 partners are cautiously optimistic about the future pipeline of M&A work for the final quarter of 2015 and into next year.

Browne says: "I'm very positive. The market feels strong and I think it will continue. That said I think there's some pretty big macro-economic issues looming out there that could have a dampening effect, even if for a short period. There's the whole question around Brexit, for example, and the impact that a slowdown in China could have on commodities and, therefore, M&A."

Ryde concurs, advising caution when looking ahead. "We anticipate the M&A hot streak will continue for the rest of the year and beyond," he says. "However, we've seen recent uncertainty in China which caused real stock market wobbles and in the Eurozone. While there is a sense of relative stability, I'm sure there are shocks around the corner."