International firms Speechly Bircham and Withers, whose joint headcount includes more than 600 lawyers, are discussing a merger.

A joint statement said that the firms are in ‘preliminary discussions’ and both see ‘exciting opportunities for growth in such a merger’.

Speechly Bircham was formed by a 1974 merger between Speechly, Mumford & Soames and the City office of Bircham & Co. It has 90 partners and more than 260 lawyers in total. In the year ended 30 April 2012 its turnover was £57.6m.

Withers (pictured) was formed following the merger of US firms Bergman, Horowitz and Reynolds and Withers in 2002. It claims to be the ‘world’s first international law firm dedicated to the business, personal and philanthropic interests of successful people, their businesses, their families and their advisers’.

It has over 100 partners and more than 270 other lawyers, and reported a UK turnover of £80m in 2011/12.

The statement said: ‘Both Withers and Speechly Bircham have been growing their international offering in response to changes in the global legal market and the increasing importance of private capital in the world economy.

‘There is still a lot more work to be done before any final decision can be reached and so we will not be issuing any further comment at this stage.’