"Some of the details are still being worked out, but the deal is pretty much done," said Sen. John Ensign, R-Nev., one of the negotiators. Senate Minority Leader Mitch McConnell, R-Ky., called it an agreement on the "parameters" of a bill.

"Is everything worked out? No, not everything, but we are very close," said Senate Majority Leader Harry Reid of Nevada. "We have arrived at a point where we can move forward with this."

The agreement also could lead to votes to extend dozens of other targeted tax breaks that expired last year or that are about to expire, including one that allows people to deduct a portion of their state and local sales taxes, senators said.

The provision allows taxpayers to choose whether to deduct state income taxes or a portion of sales taxes from their taxable income. Nevada is among the states that does not levy a state income tax, and its citizens have made broad use of the sales tax deduction as an alternative.

The bill would extend the sales tax credit through the end of 2009, according to Senate officials.

Renewable energy companies that have shown interest in boosting activities in sun-kissed and wind-blown Nevada have monitored Congress on this issue and had been frustrated by the delays.

Rhone Resch, president of the Solar Energy Industries Association, said it appeared that holdups may have dissipated.

"I think for the first time this Congress we have seen Republicans and Democrats at the leadership level working together to strike a deal," Resch said.

Resch said one important provision would lift a $2,000 cap on how much a homeowner could claim as a tax credit for installing solar equipment.

"That is by far the best legislation that has been introduced in Congress," he said.

Reid said the agreement that took shape "will create tens of thousands of jobs in Nevada and more than a million nationally."

The House on Tuesday was moving toward passage of a broad energy bill that also would extend tax breaks for renewable energy projects.

The Democratic-written bill contains an eight-year investment tax credit of 30 percent for solar and fuel cell projects, a three-year extension of production tax credits for geothermal, biomass and hydropower, and a one-year extension for wind projects.

The tax breaks were valued at about $18 billion in the House bill over 10 years, roughly the same as the agreement being formed in the Senate.