SAN FRANCISCO (AP) - IBM says federal regulators are investigating its accounting of some business transactions in the United States, the United Kingdom and Ireland.

SAN FRANCISCO (AP) IBM says federal regulators are investigating its accounting of some business transactions in the United States, the United Kingdom and Ireland.

The company made the disclosure in a public filing Tuesday, saying it learned of the investigation in August. IBM said it's cooperating with the probe, which is focused on the way IBM reported revenue for certain transactions. The filing didn't provide details.

IBM shares were down more than 3 percent in trading after the disclosure.

The company, based in Armonk, New York, announced separately that it will increase its share buyback program by $4 billion and will pay a quarterly dividend of $1.30 per share.