"A huge proportion of global business is headquartered in the US, and roughly 50% of global legal spend is there. More often than not, the global general counsel and heads of litigation are based there, whether that's in New York, Chicago or Los Angeles, so you need to be there," says Clyde & Co senior partner Simon Konsta.

During the past 18 months, Clydes has been in an expansive mood across the pond. On the back of office launches in Washington DC, Chicago and Los Angeles during 2017, last December the firm took on a team of 15 partners from collapsed US firm Sedgwick, led by insurance chair Ralph Guirgis and Los Angeles managing partner James Holmes.

The hires increased the size of Clydes' US partnership by about a third and were closely followed by a 10-strong hire in Miami, including a further two litigation and commercial-focused partners.

Having kicked off 2018 with the expansion of its Washington DC office with the addition of a nine-lawyer insurance team, including four partners from US firm Shipman & Goodwin, Clydes – which now has about 70 partners and more than 250 lawyers in the country – is showing no signs of slowing in expanding its transatlantic reach.

"What you have seen in recent months is the culmination of many months and years of planning," says Konsta. "This goes to the focus for us in the US and North America as a whole. We are of course committed to being an emerging markets firm, and we will continue to focus on Asia, Africa and the Middle East so that we can provide solutions in those regions, but whichever way you look at it, you also need to be in the US."

Talks to set in motion the headline-grabbing hire of 45 lawyers from Sedgwick began in autumn last year, with Konsta saying that he suspects Clydes was not the only firm to have spoken with the team.

"We were lucky in the sense that we had existing partners in the US who knew and had worked with Sedgwick for many years, so it is not as if we were looking at a substantial undertaking from a standing start," he explains.

"It was a large number of partners, and when you are clearing conflicts, transferring substantial amounts of data and getting teams up and running there is obviously a logistical challenge, but I think that we have negotiated that well. It is early days in terms of the business, but the initial  view is that they have settled in well and revenues are in line with expectations. Most importantly, the clients are happy."

A substantial transatlantic merger – which we are unlikely to do – is effectively piggybacking on the status of the US firm

Konsta says the US expansion has been carried out with a "laser-like focus" on sectors and practitioners, without which, he argues, the firm risked ending up with "mid-table mediocrity and no meaningful brand presence".

Konsta adds: "Unless you decide to embark upon a substantial transatlantic merger – which we haven't done, are unlikely to do, and which is effectively piggybacking on the status of the US firm – you need a very clear sectoral strategy and you need to be recruiting the very best market leaders from the best firms in those areas."

Discussing the firm's current position, Konsta says they have "very good penetration with some clients", but acknowledges that there is more work to be done. He says the firm's key areas of focus are the "core pillars" of its global businesses, including infrastructure, commodities and energy, as well as building out its corporate and commercial capability.

Aside from expanding existing practice areas, Konsta says the firm is looking at how to best exploit the value of its existing offices, putting in place "integration programmes" to ensure that happens.

"Since November 2017 we have had a North America board chaired by San Francisco managing partner Bill Casey," he says. "It has US and Canadian representatives at a senior level and the primary function is to take a North American view of what we are doing and to ensure proper integration across borders – and within borders – and also to look at growth opportunities.

"We have also created some client-focused groups within the US, with representatives of each office and practice areas, to talk about shared opportunities and client challenges."

As well as Casey's chair role, former senior partner James Burns has since late 2016 served as head of Americas. The position makes Burns – who works in tandem with chief strategy officer William Isaac – responsible for overseeing growth in the Americas and also for the integration of offices in Canada, the US and Latin America.

Konsta also says that following Clydes' expansion in California, building out the firm's capability on the west coast of Canada is also on his radar. "I am mindful of US-headquartered companies that have major businesses in Canada and vice versa," Konsta says. "I am sure there is more that we can do, and having just expanded in California, at some point we would like to build a west coast capability in Canada too, most likely in Vancouver."

As for the foreseeable future, Konsta refuses to be drawn on whether Clydes has any existing expansion plans, saying only that the firm regularly gets offered new opportunities and that they are getting "more frequent and more exciting".

"We have no set plans right now to grow out in specific locations, but we are looking at options and we look at them with real diligence – so in terms of more expansion, we never say never," he says. "We are very excited about the US and North America, and there is a lot more to do out there."

Clyde & Co Americas expansion since January 2017

• February 2017: Ten-partner insurance and disputes practice joins from Troutman Sanders to launch two new offices in Washington DC and Chicago
• May 2017: Acquisition of 30-strong Mexico energy, marine and trade firm Garza Tello
• July 2017: Launch of ninth US office in Los Angeles
• December 2017: Acquisition of 93 lawyers and staff from Sedgwick, including a new Orange County office and a Kansas City shared-services team
• January 2018: Acquisition of 10-lawyer Miami insurance team from Hinshaw & Culbertson and five-partner Washington DC disputes team from Shipman & Goodwin