A planned 48-hour strike by rail guards at First Great Western (FGW) has been suspended, the Rail Maritime and Transport Union (RMT) has announced.
The strike was planned to start on 20 January
Talks between the company and the union had been going on since last weekend.
Guards at the rail operator, which runs services from Paddington to the West and south-west of England and Wales, had planned to strike from 20 January.
But the RMT said talks had been positive and progress made. Relations broke down over managers' duties.
General secretary Bob Crow said: "The resolve of RMT members at FGW has led the company to listen and act on our concerns and we hope a resolution can be found.
"Our strike mandate is still valid and negotiations will continue on a number of issues essential to the resolution to this dispute."
The news came ahead of a meeting in Bath on Tuesday night by a passenger group complaining about First Great Western train services.
The group, More Train Less Strain, will consider calls to stage action, including withholding fares, in protest at the level of services.
The union had taken issues with managers driving and guarding trains.
The company admitted it did use managers to crew trains on a Sunday as a "last resort" as FGW was a commercial operation working seven days a week, but that it would never compromise safety.