WHFS-FM and its progressive rock format, which are due to die at midnight tonight and reappear on the AM band next month, may be silenced for good if a group of big-band lovers has its way.

The free-wheeling format appeared to get new life last December, when some former stockholders of WHFS (102.3) purchased WEAM-AM (1390).

But on Monday, a group identified as the Committee to Save WEAM filed a last-minute petition with the Federal Communications Commission objecting to the deal.

In seeking to block the transfer of license to the WHFS group, known as Cardinal Broadcasting, the committee is arguing that WEAM's current big-band format is unique and that its listeners, who are "part of the 'public' whose interest must be served by any assignment of a license," were not considered or consulted about the sale or format change.

Ironically, that is similar to the argument made by disappointed WHFS listeners when that station was sold to the Outlet Co., which proposed a shift to an all-news format. A petition to block that sale, filed by the Washington Council for Progressive Radio, was withdrawn when WHFS announced that several of its stockholders would be purchasing WEAM.

Cardinal has indicated that it would be changing WEAM's call letters to WHFS, dropping its 2 1/2-year-old big-band format and instituting the progressive rock format that has been in place at WHFS for 15 years.

WEAM, once the top-rated radio station in Washington and the city's first 24-hour rock outlet, has experimented with a number of formats over the last 10 years, including rhythm and blues, rock and, most recently, big band. Over the past few years, both WHFS and WEAM have been near the bottom of the local Arbitron ratings.

The committee, which describes itself as an "ad hoc committee of concerned WEAM listeners," is also challenging what one lawyer calls the "wholesale trafficking in broadcast licenses."

In December, WHFS was sold to the Outlet Co. of Providence, R.I., for $2.1 million. Outlet, a media conglomerate that owns five radio and five television stations (including WTOP-AM here), was in turn purchased by Rockefeller Centers Inc. for $322 million in May.

In the meantime, Cardinal Broadcasting (whose principal owners are WHFS president Jake Einstein, his son, program director David Einstein, and lawyer David Margolious) purchased WEAM for $1 million. More recently, ABW Broadcasting Inc. (whose principal owners are former WHFS stockholders Marvin Rosenbloom and disc jockey Damien Einstein, Jake's son and David's brother) purchased WNAV-AM and WLOM-FM in Annapolis for $2.8 million.

All the sales are subject to FCC approval, and petition by the Committee to Save WEAM is one part of the FCC review process. Cardinal has two weeks to answer that petition, the committee has 30 days to comment on that reply, and then the FCC has 30 days to debate the merits of both positions. There are various appeals processes, and David Einstein said yesterday that "unless we can get FCC approval, I wouldn't expect us to be on the air until the early fall."

He added that the station's massive library and its on-air staff would be moving as a unit to WEAM and "we'll be doing the same kind of delivery, the same kind of music with the same jocks. We'll just do it harder, and, if we can, better."

The sale of WHFS to Outlet goes to settlement tomorrow. Michael Douglas, general manager at WTOP-AM, said that "our projected air date was September 1 and we're still aiming for that, but it may be mid-September" before Outlet starts operating on 102.3 FM. Douglas added that Outlet was "still holding discussions about the actual format" of the new station.