In another major trans-Atlanic merger, Denton Wilde Sapte and Sonnenschein Nath & Rosenthal have agreed to tie the knot, subject only to a formal partnership vote on the 9th June.

Dentons, in common with many mid-sized UK firms, has long been angling for a US merger in a bid to get enough clout to compete globally. And on the face of it the firm has pulled off a decent deal. Partners speak warmly of the cultural synergies and there's no real duplication of offices - with the exception of two small outposts in Brussels and Zurich, Sonnenschein is based entirely in the US. And while both firms have been underperforming in recent years, their profits are in the same ballpark, with Sonnenschein ahead at around £540k per partner compared to Dentons' £360k. However London will be by the far the biggest office in the merged firm - twice the size of New York - so it's more than just a UK bolt-on to a US firm.

Inevitably it's not all beer and skittles. While Dentons will be delighted at the acquisition of a 200-lawyer New York office, it could probably do without outposts in the likes of Walnut Creek. And Sonnenschein's last experience of London was when it opened an office in the City some 15 years ago - and almost immediately closed it, stiffing all its staff in the process. Still, Howard Morris, Dentons' CEO, is as happy as a dog with two tails, telling RollOnFriday that "the worst that will happen is we'll make two plus two equal four, and we aim to make it four and a half".

    Howard Morris. The Sonnenscheins out of his arse

Assuming the merger gets the partnership vote, SNR Denton will come into existence in September with some 1,400 lawyers. With Hogan Lovells now bedding down and SJ Berwin openly in talks with US firms, expect Heathrow to remain crowded by managing partners of City firms for the foreseeable future.

Tip Off ROF