CA chairman and chief executive officer Sanjay Kumar said his company volunteered to help the US Department of Justice and the US Securities and Exchange Commission after CA learned in December that some of its customers had been asked to supply their contracts with CA to investigators.
"As has been reported, a small number of customers were asked by the government for a copy of their contracts with CA. We approached the government and invited them to ask us instead of our customers. In response, they formally asked for the information," Kumar said.
CA did not say which customers were asked to provide their contracts and an SEC spokesman declined to comment on the investigation.
For more than a year the two government agencies have been investigating allegations that the enterprise software supplier improperly booked revenue from the sale of its products.
In November the SEC questioned several former CA employees about the company's revenue booking procedures, focusing on whether the company booked maintenance contracts with the sale of software licences to book as much revenue as possible up front, in violation of accounting rules.
CA reported a net loss of $44m (£27m) for the third quarter, as revenue fell below Wall Street expectations.