Majority Leader Bill Frist said he wanted to wrap up the entire package by the end of this week. Yet to be decided were Democratic amendments that would require better fuel mileage for US cars, including gas-guzzling sport utility vehicles.

After two days of debating how far the nation should go to curb emissions of greenhouse gases linked to global warming, the Senate bowed to pressure from industry groups who feared strict measures would be too costly and eliminate jobs.

The Senate rejected, 60 to 38, a plan offered by Republican John McCain and Democrat Joseph Lieberman which would require a cut in US carbon dioxide output to 2000 levels by 2010. The White House opposes mandatory cuts.

The same proposal failed in 2003 with a vote of 55 to 43.

The measure lost support among Democrats because of incentives added to build new US nuclear power plants, which emit no carbon dioxide, Lieberman said. "Some people on the left in our party were scared away by the mere mention of the word 'nuclear'," he told reporters after the vote.

The vote made it clear that the Senate was unwilling to go beyond a plan approved on Tuesday to coax companies to voluntarily reduce emissions with generous tax breaks for such projects as coal gasification and carbon sequestration. The plan, from Republican Chuck Hagel of Nebraska, reflects the White House's preference for a voluntary approach.

Environmental groups expressed dismay at the Hagel plan, saying it would give billions of dollars to utilities, coal producers and oil firms with no requirement to cut emissions.

BUSH PRESSES FOR BILL

President George W. Bush toured a Maryland nuclear power plant on Wednesday and put pressure on Congress to approve energy legislation that has been bottled up for four years.

"It's time for Congress to stop the debate, stop the inaction and pass an energy bill," Bush said. "They need to get me a bill before they go home in August."

Frist slated a Thursday vote on a motion to limit debate on the entire energy bill. The motion is expected to pass and set the stage for a final vote on the bill by the end of the week.

Some Republicans said they hoped the Hagel plan approved by the Senate would help defuse criticism that the United States, the world's biggest emitter of carbon, is not doing enough.

Bush will attend a Group of Eight meeting in early July, hosted by British Prime Minister Tony Blair, who wants to focus on global warming.

"Tony Blair has put unmitigated pressure on this president. He's even lobbied us individually on it, suggesting we ought to get this president to change his mind," said Sen. Larry Craig, an Idaho Republican. "The Senate spoke yesterday."

Republican James Inhofe, head of the Senate environment committee and an outspoken critic of global warming, said no stricter measures were needed.

"There's a lot of hysteria out there and the hysteria is not well-founded," Inhofe said.

However, supporters of the McCain-Lieberman plan pointed to rising ocean levels, melting icecaps atop Tanzania's Mount Kilimanjaro and other signs of warmer temperatures.

Shrinking snow in the Sierra Nevada mountains may eliminate water supplies for 16 million people, enough for all of Los Angeles, by the end of the century, said Dianne Feinstein, a California Democrat. "That's Armageddon for the fifth-largest economy on Earth," she said, referring to California.