Mills & Reeve, East Anglia's biggest law firm, is planning to merge with Birmingham firm Martineau Johnson.
Mills & Reeve managing partner Duncan Ogilvy confirms that the two firms are talking to each other.
"Martineau Johnson is one of the premier business law firms in the region, so they are logical people for us to talk to," says Ogilvy.
"Our Birmingham office has been very successful since our move there last year, but we have been very clear that we would not develop a business-based practice in the Midlands on our own."
Ogilvy revealed to The Lawyer in August that Mills & Reeve intends to expand its 100-lawyer Birmingham practice into the private sector from its current medical negligence and insurance base.
Martineau Johnson managing partner David Gwyther is cautious about the talks, stressing it is "early days".
But he adds: "We have a clear strategy to develop our corporate client base. Sometimes we talk to other firms to see whether a joint operation could benefit our clients. Mills & Reeve is an excellent firm."
A vote in principle on the merger is expected soon. The merger would create a 90-partner, 360-lawyer firm with offices in Birmingham, Cambridge, Norwich and Cardiff.
The firms are financially compatible - Mills & Reeve's profits per partner are £135,000 while Martineaus' are £130,000, according to this year's The Lawyer 100 survey.
The firms share strengths in intellectual property. Mills & Reeve has ridden the wave of the biotechnology boom in Cambridge, while Martineaus has one of the highest-rated IP practices in the Midlands.
When Mills & Reeve's Birmingham office opened last year, the firm said it would not compete with former ally Wragge & Co, as it would cover only insurance-related work. Wragges has the highest-rated IP practice in the Midlands.
Wragges and Mills & Reeve were both members of Norton Rose's M5 referral partnership which broke up last year.
Wragges' managing partner Quentin Poole says of the plan: " It makes a lot of sense."