Houston-based Seadrill Americas Inc., the U.S. arm of Bermuda-based and London-operated Seadrill Ltd is cutting jobs after losing a contract from BP according to a letter to the Texas Workforce Commission.

BP Exploration & Production Inc. informed Seadrill that it intends to cancel its contract for mobile offshore drilling unit services on the West Sirius Rig in the Gulf of Mexico. The rig will begin preparations to shut down and be placed out of service during the next three to six months.

In its Worker Adjustment and Notification Act letter to the TWC, Seadrill described the contract as a “major contractor with a principal client.”

Seadrill will eliminate 159 offshore jobs and four onshore jobs assigned to the West Sirius Rig. The jobs will be cut during April and May and beyond.

The company might offer transfer offers to a small number of affected employees, but none have been extended at this time.

None of the affected employees are represented by a union, and they do not have bumping rights, meaning higher-ranked workers whose jobs are eliminated cannot take lower-ranking jobs.

Although the cuts are expected to be permanent, all affected employees with a satisfactory work history are eligible for re-hire if other opportunities become available.