Oslo- Two executives of energy group Statoil Hydro resigned with immediate effect Tuesday after a probe was published into payments made in connection with a 1999 oil deal in Libya.

The probe was launched a year ago when energy giants Statoil and Norsk Hydro merged their energy operations.

The payments were made to a consultancy company in connection with the deal, and came to light during the merger talks.

Two law firms based in Norway and the United States investigated the matter and issued a report Tuesday suggesting that "Hydro failed to disclose problematic issues to Statoil in the due diligence of the two companies operations prior to the merger."

The report was to be handed to the Norwegian National Authority for Investigation and Prosecution of Economic and Environmental Crime, as well as the US Justice Department and the US Securities and Exchange Commission (SEC).

Eivend Reiten, board chairman of the merged group, stepped down when the probe was launched but remained CEO of Norsk Hydro where aluminium forms the core business.

On Tuesday, Hydro's board chairman said Reiten was unaware of the transactions. (dpa)