Offshore drilling contractor Transocean ( RIG) said second-quarter revenue will be at or near the first quarter's top line as a result of downtime on several rigs and a labor strike in Nigeria.

The Houston-based company said it now expects revenue in the quarter ending June 30 to be around the first quarter's $616 million. Analysts expect $616.98 million, on average. Revenue was $646.2 million in the second quarter last year.

The company expects the strike in Nigeria to lower revenue by about $10 million. Unexpected downtime on several rigs and an incident on the Discoverer Enterprise will also hurt revenue growth, Transocean said.

Discoverer Enterprise, a deepwater drillship currently located in the Gulf of Mexico, had a riser separation on May 21. An investigation is taking place and preparations are being made to restart operations in the coming weeks.

Analysts expect Transocean to earn 7 cents a share in the second quarter. The company earned 25 cents a share in the year-ago second quarter.

Shares of Transocean were down about 2% recently to $23.39.