GenCorp announced yesterday that its subsidiary, RKO General, has agreed to sell radio stations WGMS-AM in Bethesda and WGMS-FM in Washington to an investor group as part of a settlement of a 22-year battle with the Federal Communications Commission.

Classical Acquisition Partnership, which includes two Washington businessmen and a Bethesda attorney who owns a small chain of radio stations, has agreed to pay RKO $22.3 million for the two classical music stations.

The investor group also will pay a total of $10.4 million to several competing applicants for the station licenses.

The principal partners in Classical Acquisition include brothers Mitchell P. and Steven M. Rales, who own much of Danaher Corp., a Washington-based industrial conglomerate, and John VerStandig, a Bethesda attorney who heads VerStandig Broadcasting Inc., which owns low-power radio stations in Cambridge, Md., Harrisonburg, Va., and Waynesboro, Pa.

RKO is being forced to sell its 12 radio and two TV stations to settle a longstanding dispute with the FCC, which found that RKO was unfit to hold broadcast licenses because of offenses that included lying to the FCC, overcharging advertisers and falsifying records.

RKO officials have protested the order, saying it contained errors, but the company has gone ahead over the past year with plans to sell the stations.

So far, it has agreements to sell five of its radio stations and a television outlet; all, including the WGMS sale, must be approved by the FCC.

Classical Acquisition won the bidding for WGMS over several other suitors. Earlier this year, the leading candidate to take over the stations appeared to be a group headed by Larry J.B. Robinson, former owner of the J.B. Robinson jewelry store chain. But that proposal ran into problems last spring.

Other bidders included a group led by former Treasury secretary William Simon, and Ragan A. Henry, a prominent Philadelphia lawyer and pioneer in black broadcasting.