However, the White House has said it would veto the measure if the renewable electricity standard was in the final bill and Senate Republicans have threatened to filibuster the legislation over the requirement.

Under Senate rules, 60 of the chamber's 100 members are needed to end debate on a bill and have a final vote on the legislation.

"It appears, at this stage, that we're not going to be able to keep in the bill the renewable electric standard," Reid told reporters on Capitol Hill. "We don't have enough votes to keep it in."

Southern utilities lobbied strongly against the electricity standard, arguing there was little renewable energy sources like strong wind currents in their region of the country to generate power and that's why they relied more on cheaper coal.

Reid said he wants to vote on Thursday to limit debate on the energy bill so the measure can clear Congress before lawmakers adjourn for the year.

After the Senate votes, the legislation would have to go back to the House for its approval and then be sent to President George W. Bush to sign into law.

The White House is likely to welcome the renewable electricity standard being dropped, but it's unclear if the legislation's multibillion-dollar tax package will be modified enough to escape a presidential veto.

The White House has warned that the president would reject the bill if it came to his desk in its current form with billions of dollars in taxes on big oil and natural gas companies.

Democrats sought the new industry taxes to help offset the loss of federal gasoline tax revenue that would occur under the centerpiece of the legislation, a 40 percent increase in the fuel efficiency requirements for US cars and trucks by 2020.

Boosting vehicle fuel efficiency to 35 miles per gallon, the first such increase mandated by Congress in over three decades, would help could cut US oil demand by 1.1 million barrels a day when fully implemented.

Reid said he would offer a modified version of the bill's tax provisions, but he said they still totals US$21 billion like the House's version. Reid said "there's far more than 60 votes" in the Senate for clearing the revised tax package.

However, Pete Domenici, the top republican on the Senate Energy Committee, warned his colleagues that passing the bill with taxes opposed by the White House will doom the measure.

"It's a wasted time and effort to pass a bill with US$21 billion worth of the taxes," Domenici said. "It can't be done."