Maersk Drilling has had one of its drillships returned to the company early from customers Marathon Oil and ConocoPhillips.
The company said the Maersk Valiant had been on contract for drilling up to September next year.
Maersk Drilling will receive compensation for the early contract stop, which it said will offset the loss of profit.
A spokesman for Maersk Drilling said the contract termination had shown the “extremely challenging” conditions in the offshore market for oil and gas.