WASHINGTON (AP) _ Stouffer Food Corp. has been ordered to stop misrepresenting the amount of sodium or any other ingredient in its frozen food products, the Federal Trade Commission said Tuesday.

The FTC order upholds an administrative law judge's 1993 determination that Stouffer made false and misleading claims about the levels of sodium in its Lean Cuisine food line.

However, the commission said it broadened the judge's order, which only prohibited misrepresentations about sodium content.

Officials of Stouffer, which is based in Solon, Ohio, were unavailable for immediate comment.

In an appeal of the 1993 decision, Stouffer said the advertising campaign claimed only that reformulated Lean Cuisine products had a reduced or lower amount of sodium, rather than a low amount of sodium, the FTC said.

The $3 million Lean Cuisine advertising campaign ran from January 1990 to August 1991. Ads appeared on radio and in such magazines as Ladies Home Journal, People and Good Housekeeping.

The FTC voted 5-0 to issue the order, which becomes binding 60 days after it is served on the company.

Commissioner Mary L. Azcuenaga noted that the ad campaign followed a complaint Stouffer filed with the Council of Better Business Bureaus about a competitor's advertising.

In the complaint, Stouffer argued that the competitor misled the public by stating sodium content in grams rather than milligrams, as was customary, Azcuenaga said.

When the council declined to act on the complaint, Stouffer began using the phrase ''less than 1 gram of sodium'' in its own advertising, the FTC said.