London - Britain's Serious Fraud Office widened its investigation into Rolls-Royce to examine allegations of suspected bribery in Nigeria, the Financial Times reported on Thursday.
Rolls-Royce, the world's second-largest maker of aircraft engines, said in 2013 the SFO had launched a formal investigation into concerns about possible bribery and corruption in China and Indonesia.
The publication said the probe had now spread to examine Rolls-Royce's former energy operations in Nigeria.
"We are co-operating with the authorities," said a Rolls-Royce spokesperson. "We do not comment on the subject of ongoing investigations nor on the countries in which those investigations are being conducted.
"We have made it clear that Rolls-Royce will not tolerate business misconduct of any kind."
Rolls has over the last two years been hit by cancelled orders from oil industry customers for power systems after a plunge in the oil price and a slowdown in demand for the high-margin aftermarket servicing it provides for older aircraft engines.
It downgraded profit forecasts three times last year.