UK firm RPC has formed an alliance with US firm Hinshaw & Culbertson to act and pitch together on transatlantic insurance work.

The two firms had been working closely together during the past 18 months but more advanced talks began this January, with RPC global insurance head Simon Laird visiting Hinshaw's leaders in New York.

The firms, which are both highly rated for insurance work, will now work together on client marketing and pitching and will use split teams on transatlantic insurance matters, according to Laird, in particular across directors and officers liability, complex coverage, professional indemnity, medical and marine insurance lines.

In a statement, he said: "Our insurer clients face increasingly global challenges. As far as legal services go, we believe in working with the best local firm for the job. But the US is different because it is such a large and mature insurance market. By joining up with Hinshaw we can develop targeted products, solutions and learnings [that] can benefit our clients across both the UK and US."

Hinshaw insurance co-chair Scott Seaman said the firm has found its "British cousin" in RPC. He added: "RPC [is] a firm that has a very similar approach to ours, a great stable of lawyers and a team committed to understanding the business environment we're in."

Seaman said both firms will earn new relationships from the alliance and continue to share a number of existing clients. He added that the relationship would not be exclusive: "We're not going to lose the forest through the trees. This alliance is for the benefit of our clients and if they already have a relationship with another UK firm, they can use them."

Hinshaw is headquartered in Chicago and has 21 offices across the US, with the highest headcounts in Chicago, Los Angeles and Coral Gables, Florida, according to ALM Intelligence database Legal Compass.

The US firm, which comes in at 134th in The American Lawyer rankings, has approximately 450 lawyers in total including 102 equity partners, and had gross revenues of $217.2m in 2018.

RPC had lower revenues in 2018 with £117m ($152.2m) and is smaller by headcount, with 355 lawyers in total including 82 partners, but revenues per lawyer for the two firms are only 15% out – £317,800 for RPC and $479,000 for Hinshaw in 2018.

The alliance comes amid leadership change at the US firm. Hinshaw named litigation partner Peter Sullivan as its new chairman last week, and committed to increasing head count and revenues at the firm after three years of declines according to Legal Week sister title The American Lawyer. The firm most notably lost 10 lawyers including two partners to Clyde & Co in Miami in 2018.

It is the second such tie-up in the space of a week, after Taylor Wessing and Wilson Sonsini announced last week they had agreed to target tech and life sciences work together.

RPC has made a late move into the US market with the Hinshaw alliance, compared with other UK insurance-focused firms such as Clyde & Co, Kennedys, and HFW – which all began ramping up their US presence in 2017.

Laird said RPC has had a "completely different" focus to these firms, which have been "looking at market share in a different way".

He added: "We're very focused on what the benefits and solutions are for our clients, which won't get distracted in the noise of trying to grow a massive business as quickly as possible."

Laird said the recent impetus for RPC and other insurance-focused firms to develop their US capability is market-driven: "Between 2011 and 2016, Lloyd's [of London] paid out £68bn of claims, half of which were related to US losses. A big part of our clients that sit in the Square Mile spend their waking days thinking about their exposures in the US. It's provided a real need for us to get together and work with Hinshaw for those clients."

Clyde & Co, who has been in the US since 2006, now has nine offices in the region and increased the size of its US partnership by a third with a spate of US hires, including 93 lawyers from now defunct Sedgwick.

HFW and Kennedys went down the merger route in 2017, with HFW tying up with Texas firm Legge, Farrow Kimmitt McGrath & Brown, and Kennedys with Carroll McNulty & Kull.

Other UK firms with a strong insurance practice to have a presence in the US include: DAC Beachroft, which opened a Miami office in 2015; DWF, who has an office in Chicago and formed its own US insurance alliance in October last year; and Herbert Smith Freehills, which has a 40-strong New York office that launched after its 2012 tie-up.