IBM Corp said on Wednesday that it is cooperating with U.S. regulators on an investigation into how it reports revenue from its cloud computing business.

Its shares fell 1 percent to $193.89 in pre-market trading.

IBM said it learned of the investigation, being conducted by the U.S. Securities and Exchange Commission, in May. The company made the disclosure in its quarterly report filed with the SEC.

On July 25 a U.S. judge signed off on a 2011 settlement IBM made with U.S. regulators over charges of foreign bribery after IBM agreed to a two-year reporting requirement on accounting fraud or bribery as well as federal investigations.

IBM in March 2011 agreed to pay some $10 million to resolve SEC charges over improper gifts to government officials in South Korea and China.

On Wednesday IBM also repeated a disclosure it made on April 30 that the Department of Justice is investigating allegations of illegal activity by a former IBM employee in Poland, as well as transactions in Argentina, Bangladesh and Ukraine.

It said that the Justice Department is also still seeking information regarding the company's global FCPA compliance program and its public sector business.