Only 200 of the Metronet staff who maintain London Underground trains are to be transferred to Bombardier rather than the 700 originally proposed. They will transfer under Tupe regulations as part of a deal for new trains which will be maintained by the manufacturer.
The long-running dispute came to a head in mid-April when the RMT union called on more than 2,000 Metronet-employed train maintenance staff to begin a seven-day overtime ban followed by strike action.
Metronet said that in the light of what it called "unreasonable behaviour" from the RMT it had decided to agree that a further 49 maintenance managers - the subject of a RMT ballot - would remain in Metronet employment.
The dispute follows Metronet's contract with its shareholder Bombardier to supply and maintain 237 new trains - for the Victoria tube and all sub-surface lines - from 2009.
After the RMT raised concerns, Metronet put forward a compromise agreement that would transfer only 249 staff - primarily managerial and technical specialists.
But following the RMT's April call for industrial action, Metronet claimed the union was holding London to ransom.
Mark Cooper, who heads asset performance for Metronet, said: "The RMT was prepared to stop London for the sake of 49 fleet maintenance managers transferring from one private company to one of Metronet's shareholders and we were not prepared to see hundreds of thousands of passengers disrupted and businesses lose millions of pounds over the transfer of 49 staff."
He added: "The transfer of train fleet maintenance staff to Bombardier Transportation is the sensible option for London's Tube in the long term." Metronet will now continue with the transfer of 200 staff to its shareholder company Bombardier Transportation.
The RMT said it suspended the action after Metronet withdrew plans to transfer RMT members and posts to other companies.
The union also reported that Metronet had agreed that escalator refurbishment would be brought back in-house and that it would talk with the union about returning lift refurbishment and cleaning contracts in-house.
General secretary Bob Crow said: "This is the sensible outcome we sought from the start, and it means quite simply that there will be no out- sourcing of our Metronet members' jobs."