General Motors Corp. says the U.S. Securities and Exchange Commission is asking it for information about how it has been estimating and reporting retirement plan benefit obligations.[@@]

General Motors, Detroit, says in a statement that the SEC subpoena also asks about other matters, such transactions between it and Delphi Corp., Troy, Mich., a parts supplier that recently filed for bankruptcy court protection.

The subpoena also covers pension funding obligations and other post-employment benefit funding obligations related to the Delphi bankruptcy filing, General Motors says.

General Motors says it is cooperating with the SEC investigation but has no further comment about the matter.

A competing automaker, Daimler Chrysler, says the SEC has asked it about the methods it, General Motors and other automakers have been using to come up with the interest rate assumptions needed to make pension liability forecasts.