Weightmans insists that Read's unannounced departure two weeks ago was amicable and nothing to do with the failed merger talks.
Read, who was unavailable for comment, acted as Weightmans' spokesman during the talks and was an enthusiastic advocate of the Liverpool practice's strategy of becoming a national firm.
The tripartite talks collapsed in April when London firm Kennedys withdrew, but Kennedys continued talking with Jacksons.
Then in May Weightmans withdrew from its talks with Jacksons, to the Newcastle firm's dismay.
Read joined Weightmans in January 1997 from Central Law Training where he was chief executive to the management division. He was hired by Weightmans' then senior partner Tony Summers following a management training course he attended at which Read was the speaker.
Deputy senior partner Ian Evans said: “Martin left on an amicable basis. Our arrangement had run its course.”
According to Evans, Read had been brought in by Weightmans to put in new management systems, including new finance and marketing systems, which are now in place.
Commenting on Read's departure, a partner at a rival North West firm said: “Perhaps it highlights the problems involved in having a professional chief executive in a firm where the equity partners are effectively the shareholders.”