Union officials believed the national executive of UNiFI would be hardest to convince.
The new organisation - it would be the largest finance union in Europe - is set to be established next summer after ratification by ballots of members. Union officers said yesterday that further mergers were expected with other employees' groups, including staff associations in the building society sector.
Union activists are keen to present a united front against management in the face of large-scale redundancies in the industry and company mergers. The union amalgamation will also deliver considerable economies of scale for the new union as membership continues to decline.
Paul Snowball, general secretary of UNiFI, said the new organisation would bring an end to divided representation at banks and would create a "cohesive and powerful" new grouping.
It is likely that moves towards amalgamation with the MSF white collar union and IPMS, the union for scientists and technologists in the public sector, are now likely to be abandoned. A special conference of the UNiFI will meet on 23 October to discuss the executive's recommendation.
Rory Murphy, leader of the NatWest Staff Association, described the decision by UNiFI as "fantastic news" and predicted his executive would make a similar decision today. "We have been pushing for this for two years," he said.
Ed Sweeney, general secretary of Bifu, said that previous attempts at merger had broken down, because of personality clashes. "Now the old animosities have been put aside and finance workers can look forward to a strength which a united front will give them," he said.
He urged the Lloyds TSB staff association to join and said he believed that in the long run it was possible it would include MSF and IPMS. The new organisation will remain unaffiliated to the Labour Party, but it is believed that the bigger the union the greater will be its influence on government.