WASHINGTON -- About 40% of the nation's local broadcast stations want to shut off analog broadcasts by next week, raising concerns that thousands of Americans soon could lose TV service despite Congress's recent decision to postpone the digital TV switch.

Congress approved delaying the mandatory switch to digital-only television to June 12, but local stations can ask to switch earlier than that. Many want to do so, hoping to save thousands of dollars they would have to pay to continue broadcasting in both analog and digital for a few more months.

Lawmakers didn't anticipate that so many stations -- nearly 2 in 5 -- would want to shut off analog signals Tuesday, and the development raises the likelihood that some consumers will become even more confused about what to do. At the Federal Communications Commission, officials are considering denying some stations' requests so communities won't be left without at least one local channel.

"It's important to understand that while a significant number of broadcasters want to shut off their signals early for economic reasons, the FCC will work hard to ensure entire markets aren't blocked out," said Robert McDowell, a Republican FCC commissioner. Interim FCC Chairman Michael Copps declined to comment.

Most Americans won't be affected by the switch to digital because they subscribe to cable or satellite TV services. About 20 million U.S. households rely on free over-the-air TV, although millions of viewers have already prepared for the digital switch by installing set-top converter boxes. Nielsen Co. recently estimated that about six million homes nationally are unprepared for the switch.