WASHINGTON (Reuters) - U.S. Senate talks on a climate control bill were progressing with lawmakers looking at possible alternatives to the cap-and-trade plan for reducing carbon dioxide emissions, key U.S. senators told Reuters on Thursday.

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"Comprehensive climate change (legislation) means pricing carbon and setting a target for reduction," Senator John Kerry, a Democrat and one of three lawmakers leading efforts to hammer out a compromise climate bill in the Senate, told Reuters.

Kerry was referring to President Barack Obama's call for a "comprehensive" bill, which he issued during Wednesday's State of the Union address to Congress.

"It's open to how you price carbon. People need to relax and look at all the ways you might price carbon. We're not pinned down to one approach," Kerry said.

In his speech to Congress, Obama did not specifically state the need for a market-based cap on emissions, an omission that some thought meant wide-ranging climate control legislation would not be sought this year.

Kerry strongly rejected such a conclusion, saying, "I just don't agree with that interpretation at all."

While the Massachusetts senator said he did not want to be pinned down to a specific deadline, he said he plans to outline a comprehensive bill, possibly so that legislation could be considered this spring. "We are writing and drafting; we're pulling together the titles" of a bill.

Senator Lindsey Graham, a Republican who is also working on the compromise bill, told Reuters that President Barack Obama's State of the Union speech opening the door for nuclear power and oil drilling helped efforts for a bill that could include "a hybrid system" for reducing U.S. carbon emissions.

In the speech on Wednesday, Obama acknowledged some people doubt the science of climate change but said it was important to move ahead on clean energy such as wind and solar power to compete with countries like China and India in the low-carbon economy.

Graham said that acknowledgement and an emphasis on nuclear could gain support for the bill. But he added it was "yet to be determined" if senators could come up with a bill that could pass.

Kerry and Graham are working with Senator Joe Lieberman, an independent, to include incentives for nuclear, offshore oil drilling, and clean technology jobs in the legislation.

The bill has been delayed in the Senate by the healthcare debate, as well as opposition from most Republicans and many moderate Democrats.

Legislation faces an uphill battle as lawmakers from oil and coal producing states say it could raise energy prices.

Graham said cap-and-dividend, under which carbon emissions would be limited but trade of pollution permits would be prohibited, could be one option.

A carbon tax has little support in Congress, he said.

(Additional reporting by Timothy Gardner)