Walker Martineau is being swallowed up by City firm Penningtons - and faces a legal dispute with a partner cast off from the merged firm.
Clinical negligence partner Phyllis Bennett claims she was told on Friday (24 March) that the merger was going ahead and there would not be a place for her in the new firm.
The rest of Walker Martineau's lawyers will be absorbed into Pennington's four existing offices in the south east of England, and the new firm will keep the Penningtons name.
Bennett says: "I was told by Peter Hawley, the senior partner, and Richard Underwood, the managing partner, that the firm was going ahead with a merger with Penningtons. I was told that there would not be a place for me in the new firm.
"I have received nothing in writing nor have I had notice terminating my employment as a salaried partner."
Underwood says: "Penningtons does do her sort of work but the way she wanted to do it is different to the way they are doing it. The decision was taken by both sides."
But Bennett says any suggestion that she is leaving by way of mutual agreement would be misleading, and she is taking counsel's advice.
Penningtons' managing partner Lesley Lintott will remain at the helm of the firm, with Underwood returning to full-time private client work.
Lintott says she was approached by Walker Martineau for a merger through her accountant, which advises both firms.
She says: "The person that deals with us approached me and said would we be interested in them because they were interested in us. One always looks - but a lot of these approaches fall off immediately. This just seemed to fit."
Both firms are founder members of international law associations and cite their worldwide links as attracting them to each other.
Penningtons is a member of the 12-strong European Law Group, Walker Martineau of the 50-strong network Multilaw.