Gordons Wright & Wright and Cranswick Watson are merging to create one of the largest firms in Yorkshire.
The new firm, to be called Gordons Cranswick, will have 31 partners and 79 fee earners out of a total staff of 200.
The link-up gives Bradford and Keighley-based Gordons its first Leeds operation.
An insider in the city says: "Gordons wants to get into Leeds and it is actually the dominant player in the merger. The Bradford market is disappearing."
Gordons' senior partner Richard Wilson confirms that establishing an operation in the city was a prime consideration.
"We have been considering expanding into Leeds for some time and have had a number of approaches from Leeds firms," he says.
"But we were determined we would only take this step when the time was right and when we found the right partner."
Cranswick Watson managing partner Peter Halliwell says: "Gordons has an enviable reputation for its contacts and client base. We will gain from its resources and expertise in areas of work that fit well with our own."
The firms' main practice areas are commercial property, litigation and private client.
The merged firm will continue to concentrate on commercial and private client work. It will also offer litigation and family law advice.
Wilson and Cranswick Watson senior partner David Coates will become joint senior partners of the new firm.