Penningtons Manches is to merge with London shipping specialist Thomas Cooper to create a £90m firm, the latest development in ongoing mid-tier consolidation.

The merger is due to go live on 31 June and the combined firm will be known as Penningtons Manches Cooper. Thomas Cooper managing partner Tim Kelleher will join the management board with other partners from that firm set to join its strategy board.

Speaking to The Lawyer, Thomas Cooper partner Mark Sachs said the firm had been looking for a “Goldilocks merger” for around five years. “We have pursued an international strategy and have five foreign offices but given we realised we needed greater size in London to take what we have forward,” he said. “We wanted to find a firm that was litigation-oriented and thought there were real synergies with Penningtons Manches, and we found we really liked the main leadership team and the partners we’ve met.”

Penningtons Manches chief executive David Raine added that his firm had been seeking new growth opportunities in the wake of the challenges being thrown up by Brexit, especially in litigation and arbitration. “We were impressed with Thomas Cooper’s marine work, which is a new sector for us, but also with their international trade and arbitration capability,” he said.

The merger will give Penningtons Manches an international network beyond its sole non-UK office in San Francisco. Thomas Cooper occupies an almost unique position in the London market in that it is a shipping boutique that is large enough to have an international network, with 26 partners and offices in London, Madrid, Paris, Piraeus, Sao Paulo and Singapore.

Penningtons Manches marketing and development director and management board member Rolland Keane said that a presence in key arbitration and private wealth jurisdictions such as Paris and Singapore was another key attraction of Thomas Cooper.

“Looking at the plan for private wealth, Singapore is a key jurisdiction for us to be active in, and we are, but to exploit its potential in the longer term we needed more than visiting partners flying out and back again. So it is not just Thomas Cooper’s excellent client base in Singapore or the litigation and arbitration; it also gives a presence for other key areas of the business.”

Internationally, “we started out with a toe in the water, with our activity in the tech industry leading to the opening of a San Francisco office,” Raine said. “That has given us a great deal more confidence to make a move like this to a wider international footprint.”

“In five years all firms [like ours] will be increasingly intentional in focus,” he added. “Irrespective of what happens in Europe, if you look at trends like the rise of China, to focus only on domestic matters would be fairly short-sighted.”

Penningtons Manches is itself the product of a 2013 merger, between Penningtons and Manches, although it is widely acknowledged that the former firm rescued the latter after some suicidal cashflow management on the part of Manches. Penningtons had already acquired the bulk of two firms, Dawsons and Wedlake Saint, in 2011.

The firm stood 48th in the most recently published edition of The Lawyer UK 200 with revenue of £76.1m, having enjoyed rapid organic growth over the last five years. The combination is expected to take it to £90m, putting it at roughly the same size as Burges Salmon.

The eponymous Thomas Cooper set up as an Admiralty lawyer in the aftermath of the Napoleonic Wars, specialising in the now arcane law of prize, the distribution of wealth captured from enemy fleets. Apart from the addition of a banking and finance practice, the firm that bears Cooper’s name has stayed true to its origins, focusing on shipping,  international trade and arbitration work.