UNISON says Northern Care Alliance NHS Foundation Trust has agreed to resume negotiations in a dispute over overtime payments.
More than 350 workers are involved in the dispute across Royal Oldham Hospital, Rochdale Infirmary, Salford Royal Hospital and Fairfield General Hospital in Bury.
A strike planned for Monday 14 September will now be called off following the trust's commitment to talks, according to UNISON.
However, the union says staff will still walk out on Tuesday 15 and Thursday 17 September unless significant progress is made.
Picket lines are planned at Royal Oldham Hospital and Rochdale Infirmary on Thursday 17 September from 8.30am.
The workers involved include nurses, clinical support workers and housekeepers working in operating theatre services.
The dispute concerns the use of NHS Professionals to manage overtime.
UNISON claims some staff receive less for overtime shifts than they would earn on a normal shift, with some workers losing as much as £80.
The union said previous negotiations with Northern Care Alliance had stalled.
UNISON North West regional organiser Kevin Dolan said: “This is a positive step which UNISON has been calling for since the trust withdrew its previous offer.
“This breakthrough is testament to workers in the theatre department. They've stood firm and continued to deliver a high-class service while under significant pressure.
“Staff aren’t asking for special treatment. They just want to be paid the overtime rates they signed up for. There’s still a long way to go, but UNISON remains committed to securing a resolution at the earliest opportunity.”
The Northern Care Alliance runs the four hospitals affected by the dispute.
