North Sea helicopter pilots working for CHC have voted to take strike action following a pay dispute.
Pilots union Balpa said pay negotiations have been ongoing with CHC for months but the operator has failed to make an acceptable offer.
Of a 77% turnout, 94% voted for strikes and 100% voted for action short of a strike.
The ballot result means pilots could legally carry out industrial action at bases in Aberdeen, Humberside, Norwich and Sumburgh.
CHC said it had made a competitive pay offer and was disappointed by the vote for strike action.
Balpa said the action will take place on dates between 21st May and 5th November, which will be announced later.
General secretary Brian Strutton said: “Despite months of negotiations, the company have failed to offer a pay deal acceptable to our members, which is why we took the decision to ballot for industrial action.
“We have today informed CHC of the result of this ballot, and we are hopeful the company will put an acceptable offer on the table before we have to act on the mandate we received today.”
Last year CHC said it employed 72 pilots and 64 engineers at its base in Dyce, Aberdeen.
A CHC spokesman said: “It was disappointing to hear the result of the recent ballot in favour of industrial action over pay.
“We continue to negotiate with BALPA to find a mutually acceptable agreement. We believe we have made a competitive offer based on the ongoing challenging market conditions. In fact, it is the best offer made to UK rotorcraft pilots in the past five years.
“We are working on comprehensive contingency plans to ensure any disruption in the future to offshore flights is kept to a minimum.”
The helicopter firm transports North Sea workers for several operators including Chrysaor, Shell, Equinor and Total from its Aberdeen base.
It also carries out work for other firms including Neptune Energy, Spirit, Ineos, One Dyas and Orsted to southern North Sea sites from its Norwich base.
Balpa first announced in March that it was in a pay dispute with CHC.
Trade body Oil and Gas UK said the prospect of pilot strikes could threaten fresh investment to the sector.
Supply chain director, Matt Abraham, said:
“Naturally we are disappointed at the prospect of industrial action as it will add to the industry’s challenges as it strives to attract fresh investment in the North Sea to protect jobs across the sector in the long term.