The aerospace giant said it is cooperating with the SEC's inquiry and has committed no violations.

"Boeing believes that its accounting policies and practices are in accordance with the highest standards and are accurate and complete," the Chicago-based company said in a brief statement. "However, due to the early stage of this matter, the company is unable to predict what conclusions, if any, the SEC will reach."

Other companies that have publicly acknowledged SEC requests for information on how they prepare estimates used to calculate pension costs are Ford Motor Co., General Motors Corp., Delphi Corp. and Northwest Airlines Corp. All have huge pension costs.

The SEC is looking into whether changes in pension plans can create reserve funds that could be tapped to bolster revenue in difficult times. The agency says the practice is misleading for investors, but it has said it has no evidence of wrongdoing at the companies.

Boeing shares rose 60 cents to $49.56 on the New York Stock Exchange before it disclosed the SEC request. The shares are up more than 17 percent this year.

The company is scheduled to report third-quarter earnings next week.