The U.S. House of Representatives has voted to delay a transition to all-digital television broadcasts until June 12, in an effort to prevent millions of residents from losing their TV signals.

The House on Wednesday voted 264-158 to approve legislation, already passed by the Senate, that would extend the Feb. 17 deadline for U.S. television stations to switch from analog to all-digital broadcasts. The vote was largely along party lines, with Democrats supporting the measure and Republicans voting against it.

The conversion is needed after Congress, in late 2005, passed legislation requiring U.S. TV stations to move to all-digital broadcasts and abandon analog spectrum between channels 52 and 69. Much of the cleared spectrum, in the 700MHz band, was sold in auctions that ended in March 2007, and many spectrum experts say the spectrum is optimal for wireless broadband services.

Many U.S. residents aren't ready for the transition, Democrats argued. Nielsen, the TV survey company, said in mid-January that 6.5 million homes, nearly 6 percent of homes in the U.S., didn't have the converter boxes necessary to receive digital broadcasts. Older TV sets that receive broadcasts over the air would need converter boxes; customers of cable and satellite TV service do not.

"It's clear to me that the only way to avoid a massive disruption ... is to delay the transition," Representative Rich Boucher, a Virginia Democrat, said.

The legislation now moves to U.S. President Barack Obama for his signature.

Obama called for a delay in the digital TV (DTV) transition in early January, after the U.S. National Telecommunications and Information Administration (NTIA) said its TV Converter Box Coupon Program, with a US$1.3 billion budget from Congress, was out of money. The NTIA program provided $40 coupons for U.S. residents to purchase the converter boxes, and as of early this week, there were 3.7 million households on the waiting list, Boucher said on the House floor.

But Representative Joe Barton of Texas and other Republicans said the delay could cost TV stations millions of dollars to maintain both analog and digital equipment. In addition, public safety agencies including police and fire departments need some of the 700MHz spectrum to better communicate with each other.

During the Sept. 11, 2001, terrorist attacks on the U.S., some emergency responders couldn't communicate with each other because they were using different devices on different areas of the spectrum.

Emergency responders "desperately need that spectrum," said Representative Cliff Stearns, a Florida Republican.

Even after a delay, it's unlikely that all U.S. residents will be ready for a transition, Republicans said. It's difficult to get more than 95 percent of people to do anything, said Representative Lee Terry, a Nebraska Republican.

But several major public safety groups have endorsed a delay in the transition, as have AT&T and Verizon, two large winners during the spectrum auction, Boucher said. Public safety agencies use TV to communicate with their communities, and those organizations are more concerned about constituents losing TV signals than a short delay, he added.

The bill also allows broadcasters to switch to digital broadcasts before June 12, Boucher said.

The House rejected an effort by Barton to require TV stations broadcasting in spectrum designated for public safety to give it up as scheduled this month.