Merger talks between Manchester commercial firms Cobbetts and Halliwell Landau have broken down following protracted negotiations.
In public statements the firms said the decision not to go ahead with the merger, which would have created Manchester's largest commercial law firm, was amicable.
But although they played down the significance of the move, at one stage they were optimistic it would succeed.
Cobbetts managing partner Michael Shaw said the "interesting" talks "enabled us to walk away with even stronger convictions about the type of firm we are".
Halliwells senior partner Roger Lancaster said both sides had agreed "a merger would not have been beneficial for either firm's long-term interests".
It is understood that a key stumbling block during the talks concerned the distribution of profits between the two groups of partners following a merger. Although both practices had anticipated making the same gross profit this year of around £8.5m, there was disagreement over how the money should be distributed.
Halliwells wanted a 60/40 split of the equity based on its projected profits, but Cobbetts thought that was too much.
An ex-Cobbetts lawyer said the firms were so different there would have been "blood on the carpet" if the merger had gone ahead.