The U.S. Securities and Exchange Commission has started aninformal inquiry into private equity firms, asking for a broadrange of documents on how the funds value assets and who invests inthem.

Among issues regulators are examining is whether firms useinflated valuations to attract investors when marketing new funds,said a person familiar with the matter, who asked not to beidentified because the inquiry isn't public.

The agency's Los Angeles office last year sent letters toseveral firms asking for details on fund investments and thevaluation of assets, as well as communication with clients,according to the copy of a letter obtained by Bloomberg News. Firmswere asked to produce the documents by the end of last year.