Orrick Herrington & Sutcliffe is set to merge with Paris firm Rambaud Martel, Legal Week can reveal, in the most significant tie-up yet between a French M&A adviser and an international firm.

The two firms have been in discussions since the summer and have agreed, in principal, to merge by 1 January, 2006, with Rambaud’s 50-strong practice set to join Orrick’s 38-lawyer Paris arm.