(Reuters) - President Barack Obama on Tuesday will gather key Republican and Democratic senators whose support is critical to passing a climate change law, seeking to jump-start stalled efforts to overhaul U.S. energy policy.

Barack Obama | Green Business | COP15

Obama called a White House meeting with lawmakers and members of his cabinet to reinvigorate one of his top policy priorities, which even his advisers admit has suffered from the president's intense focus on healthcare reform.

The U.S. House of Representatives has already passed a bill that would require the United States to reduce its emissions of greenhouse gases 17 percent by 2020 compared to 2005 levels, roughly the same goal Washington has backed at international talks to combat global warming.

But the Senate has not passed a similar measure, and a bipartisan group of senators including Democrat John Kerry, Republican Lindsey Graham and independent Joe Lieberman are expected to produce a bill soon.

Those three senators are invited to the talks, along with Energy Secretary Steven Chu, Agriculture Secretary Tom Vilsack, and Lisa Jackson, administrator of the Environmental Protection Agency.

"I want to hear what Democrats and Republicans say about how you can move forward," said Graham, when asked whether he would present an outline of a new bill at the meeting.

He told reporters he hoped to have the outline of a compromise bill completed by the end of the month and said the discussion at the White House would touch on a sector-by-sector approach to controlling carbon emissions.

A U.S. law is seen as a key ingredient for an eventual U.N. agreement to follow up on the Kyoto Protocol, which runs out in 2012, and the Senate's failure to pass a bill last year hampered the U.S. position at December talks in Copenhagen.

Obama's meeting on Tuesday -- his first with lawmakers on a broad scale to discuss the Senate legislation -- comes just as China and India joined almost all other big greenhouse gas emitters in formally signing up to the non-binding climate accord that was reached during the Denmark summit.

Invitees include key players on climate as well as some senators whose support the White House wants for a bill.


Expectations appeared low that the meeting would lead to concrete breakthroughs.

"The president asked several of us to come down there and discuss what the future is for enacting energy and climate legislation," Senator Jeff Bingaman, a Democrat, told reporters. "I think it is a useful thing to do."

Senator Richard Lugar, a Republican from Indiana, said the meeting may be an attempt to try "to accelerate activity in the energy area."

Acceleration would be helpful if the bill is to get air time before summer, an unofficial deadline that looms before intense campaigning will begin for November elections, which could change the balance of power in Congress.

Senator Lisa Murkowski, a Republican from Alaska who has frustrated the administration by backing measures to block the Environmental Protection Agency from regulating greenhouse gases, told reporters she would speak up for a bill that focused squarely on energy rather than climate change.

"If (I) could only bring in one point, I'd put a plug in for energy only," she said.

Obama has resisted calls to split the energy and climate aspects of a "comprehensive" bill, just as he has opposed splitting his healthcare reform measures into smaller steps.

Key aspects of a the Senate bill remain a mystery, however, including whether a controversial "cap and trade" mechanism will be used to clamp down on carbon emissions from industry.

Despite pronouncements by some key senators that cap and trade was dead, Senator Thomas Carper, the Delaware Democrat who chairs a clean air subcommittee, voiced strong support for using the carbon pricing mechanism for the utility sector.

"Utilities are used to working in a cap and trade world," citing the long-standing system used to control acid rain from coal-fired electric power plants, Carper, who is not invited to the White House meeting, told Reuters.

The meeting brings together five Democratic senators who chair committees with oversight of various aspects of a climate change and energy bill, along with the senior Republicans on some of those panels.

Democratic Senator John Rockefeller and Republican Murkowski likely will want to discuss their bills to slow down or prohibit the EPA from regulating greenhouse gases.

(Additional reporting by Timothy Gardner and Ayesha Rascoe; Editing by Russell Blinch and Cynthia Osterman)