Clifford Chance has poached a partner from Norton Rose, driving another nail into the coffin of the gentleman's agreement which controlled competition for partners between the eight large City law firms.
Keith Hyman will join Clifford Chance's 35-partner corporate finance group.
Hyman says: "I understand that I am the first corporate finance partner to move from one of the big eight law firms to another."
Hyman, who acts for France Telecom, will not take any clients with him.
He is thought to be leading a team acting on France Telecom's reported interest in Orange, and on a bid for a licence for the new breed of mobile phones.
Hyman has many contacts in the telecoms groups of merchant banks.
He says: "I have had 14 good years at Norton Rose and I felt it was time to work with some new people and to have different challenges."
David Childs, head of the corporate practice at Clifford Chance, says: "His recruitment adds valuable additional resource and capability to our corporate finance practice and gives us an opportunity to gain market share of mergers and acquisitions work in the growing European telecoms, internet and e-commerce sectors."
The move seals the end of the City law firms' tradition of not poaching partners from each other after they acknowledged in January that the agreement was no longer tenable.