BP employs 6,900 staff in the Texas city in total and a BP spokeswoman said that other rig workers were also being laid off as part of a wider cost-cutting drive.

"You can always look at what you are doing to find efficiencies," she said, adding that some of the workers may be re-employed by Apache.

BP is carrying out an extensive review of its business operations after it missed production targets three times last year. In November, when it downgraded its production growth target to 3%, the company warned it would be cutting costs and changing focus.

It is selling off more mature upstream assets, like those in the North Sea and Gulf of Mexico, to raise money for new exploration in areas such as West Africa. Unions fear 5,000 jobs are under threat.

BP's chairman, Lord Browne, will announce the findings of the review next month, as the company reports annual results.