Newcastle firm Wilkinson Maughan has agreed to be taken over by Eversheds, creating the largest firm in the north east.
But it is understood that at least half Wilkinsons equity partners may become salaried, and one source at Wilkinsons said the merger was only agreed after its company law department threatened to join Eversheds on its own, taking 30 per cent of the work.
However, senior partners in the 26-partner firm dispute these suggestions.
Dissenters are also complaining that the 17-partner Eversheds' office will gain blue-chip clients such as Railtrack, while Wilkinsons will lose its name and possibly its status in the city.
Talks between the two firms began last year when Eversheds' Newcastle senior partner Nigel Robson approached Wilkinsons about a possible merger.
Eversheds was keen to gain the firm's corporate expertise, while Wilkinsons stood to boost its profits.
"I am sure Eversheds sees it as everything to gain and nothing to lose," said one Wilkinsons' solicitor. "Eversheds will get the establishment firm in Newcastle."
The new firm will overtake 36-partner Dickinson Dees as the largest firm in the north east.
But Dickinsons, which has more than half of the 30 corporate clients in the city, is claiming to be relaxed about the merger.
"We have never wanted to be the largest firm in the North East, we have just wanted to be the best," said business development partner John Flynn.
Flynn did not think the merger would radically shake-up or alter the Newcastle market because it was bringing "no new resources or skills".
The Lawyer understands the merger will be formally announced this week.
However, Robson maintained that no final decision had been made. He said: "Eversheds partners are currently meeting and there will be further meetings. No final decision has been taken."