Planned strikes by workers on South Western Railway in the dispute over guards on trains have been suspended.
Rail, Maritime and Transport (RMT) union members were due to walk out on 22 February and on 9 and 16 March.
The union said there had been a breakthrough in the row which has seen a series of strikes including over the Christmas and New Year period.
It follows the suspension of strikes on Northern Rail after the company agreed to guarantee a conductor on all trains.
RMT general secretary Mick Cash said there had been "substantial progress" in talks with the company, which he said had now offered a guarantee of a guard on services that have been in dispute.
"We need to recognise that the breakthrough on the guard guarantee that has been secured today from South Western Railway has only been achieved through nearly two years of action and campaigning by RMT members on the principle of a safe and accessible railway for all."
During the two-year dispute, which has caused disruption to some of the busiest rail services in the country, the union called for a guarantee trains will not run if no guard is available, while SWR maintained they would run in "exceptional circumstances".
An SWR spokesman said he was "pleased" the strike action had been suspended.
"We are looking forward to further constructive discussions with the RMT and are hopeful that by building on this breakthrough we can see an end to this industrial action and together build a better railway for our customers."
Paul Clifton, BBC South transport correspondent
After a year and a half of industrial action, 29 days of strikes and millions of disrupted passenger journeys, is it over?
The signs are encouraging. The RMT reckons the company will guarantee a guard on every train, including on new trains due for delivery this year which are capable of running without one.
The company has always said it would roster a guard on every train, which is not quite the same as promising that without a guard the train would not run.
The two sides were trading insults only a week ago as union members voted for a fourth time to continue the long-running action.
But earlier this month the RMT reached a similar compromise with Northern Rail, which left SWR out fighting on its own as the only big train operator still facing strikes. Not any more, it seems.
Hundreds of thousands of passengers on Britain's second biggest train operator will heave a huge sigh of relief.