Democrats in the U.S. House of Representatives neared an agreement on a climate-change bill on Tuesday and said they expected to approve it soon.

Our goal is to finish this bill by the close of business next week on the House floor, Representative Edward Markey, chairman of a House Energy and Commerce subcommittee, told reporters.

Democrats on the full committee compromised on emission of greenhouse gases, which scientists have blamed for global warming.

Many had initially sought a 20 percent reduction of emissions below 2005 levels by they year 2020, but agreed to a reduced target of 17 percent, said House Energy Committee chairman Henry Waxman, a California Democrat.

Waxman said lawmakers were still deciding how to allocate pollution permits to different industries, but said the bill would set aside 35 percent of them for utilities.

The Obama administration had called for a 100 percent auction of these permits, but has indicated a willingness to compromise on this issue.

We will have the votes for passage of this bill next week, Waxman said, standing beside Markey, a Massachusetts Democrat.

Waxman's spokeswoman, Karen Lightfoot, said later he was referring to passage by then by the committee, not the full House.

Congress breaks on Friday next week for a week-long holiday.

Democrats had set a goal of having the full House approve the climate-change bill after legislators return, but it is uncertain whether the Senate will provide its needed concurrence for it to become law.

A number of senators from coal and industrial states, Democrats as well as Republicans, have voiced concerns about the increased energy costs associated with the measure, which is a top legislative objective of the Obama administration.

Senate backers would need to muster 60 votes to clear a procedural hurdle against the measure.

House Democrats are continuing to negotiate details, but Waxman said the legislation still would require utilities to generate a portion of their electricity from renewable sources, like wind or solar power.

However, that amount has now been lowered to 15 percent with a 5 percent gain in energy efficiency by 2020, from the initial goal of 25 percent by 2025. Governors would also be able to lower that target to 12 percent with 8 percent efficiency gains, if they say the higher goal for renewables is unattainable for their state.

Beyond the U.S. legislative timetable, the Obama administration also faces a December deadline to come up with a plan to curb emissions. That is when international climate change talks take place in Copenhagen to craft a follow-up agreement to the carbon-capping Kyoto Protocol.

(Reporting by Ayesha Rascoe and Thomas Ferraro; Editing by Chris Wilson)