The staff, who work as hostesses and domestics providing catering, cleaning and laundry services, were concerned they would lose some of their holiday entitlement.
Nadine Houghton, GMB regional organiser, said: "Some members stood to lose up to 14 days annual leave entitlement as a result of not being able to book their annual leave, despite numerous requests to do so.
“Members were clear that they would not be cheated out of holiday that they are quite rightly entitled to so they decided to take action to stop Aramark robbing them of their hard earned leave. The members returned a 97% vote in favour of industrial action in a consultative ballot.
“GMB then moved to a formal industrial action ballot. Upon receiving notice of an official ballot Aramark were quick to address the members concerns and agreed to reimburse the leave that had been lost.”
Aramark was contacted by Cost Sector Catering magazine, but a spokesman declined to comment on ‘matters that have already been resolved’.