The world's largest oilfield services company Schlumberger evacuated one of its facilities in the US city of Houston on Thursday following a bomb threat, local media reported.

The facility, a technology center located in Rosharon, about 50 km south of downtown Houston, received a package with a bomb threat in the afternoon, prompting an evacuation of roughly 500 employees, according to the Houston Chronicle.

The company later confirmed in a statement that local police and bomb squad personnel were on site investigating the threat.

Hours later, Schlumberger spokesman Stephen Harris told the media that the site was cleared and the bomb threat turned out to be a hoax.

"Bomb squad folks have determined that there was really nothing in the package. It was just a hoax," Harris said.

All employees returned to the facility later and operations were back to normal by Thursday night, according to the spokesman. Investigators are still trying to determine who sent the threat.

Schlumberger, founded in 1926 by French brothers Conrad and Marcel Schlumberger, employs approximately 120,000 people worldwide. Its principal offices are in Houston, Paris, London, and The Hague.

Schlumberger is the Houston area's fourth-largest public company, based on its 2013 revenue of 45 billion US dollars, according to a Houston Business Journal research.