A woman takes pictures of the logo of Swiss power technology and automation group ABB ahead of a news conference to present the company's full-year results in Zurich, Switzerland February 8, 2017. REUTERS/Arnd Wiegmann

ZURICH (Reuters) - ABB ABBN.S said it was cooperating with anti-fraud authorities in the United States and Britain and had reported past dealings with Monaco-based engineering and construction group Unaoil, including alleged improper payments to third parties.

The Serious Fraud Office in Britain said earlier it has launched an investigation into the activities of ABB’s United Kingdom subsidiaries, their officers, employees and agents for suspected bribery and corruption.

“As a result of an internal investigation, ABB self-reported ... certain of its past dealings with Unaoil and its subsidiaries, including alleged improper payments made by these entities to third parties,” ABB said in a statement.

Unaoil in May denied a media report linking it to corrupt practices involving big oil companies and said it has been the victim of an extortion attempt by unidentified criminals.