Petronas’ upstream unit has cancelled a contract with MHS Aviation for helicopter services involving EC 225 aircraft.
Boustead Holdings said in a Malaysia stock exchange announcement that MHS, a 51% subsidiary, had been handed a 90-day termination notice earlier this month.
Boustead said MHS viewed the move as a breach of contract.
The 225 model has been grounded in the UK and Norway since one of the aircraft crashed in Norway in April 2016, killing all 13 people on board.
Petronas said in a statement that the safety of its employees was its top priority and that it had held talks with MHS before deciding to terminate the contract.
It also referred to the grounding of 225s in the UK and Norway and said many oil and gas companies had stopped using the aircraft.