Rolls-Royce said on Monday that it had won an important contract to service helicopter engines for the US army.

"Rolls-Royce has received a contract valued at $183 million (149 million euros) to service M250 engines, which power the US Army's fleet of OH-58D Kiowa Warrior scout helicopters," it said in an official statement.

The London-listed group added that the contract, to support 500 M250 engines on more than 300 aircraft, would begin in July 2012 for a year. The US army has options to extend the deal for another four years.