WASHINGTON - The U.S. Senate's failure to hold to its early August deadline to pass a major healthcare bill could complicate another of President Barack Obama's top policy priorities: the fight against climate change.

Already facing a crowded autumn schedule, Senate Democratic Leader Harry Reid said debate on legislation to expand healthcare to the uninsured will have to wait until September, as the Democratic-controlled Congress and the White House work to overcome roadblocks.

Climate change legislation is not expected to be considered on the Senate floor until October, and a spokesman for Reid reiterated that timetable still holds.

But many of the leading senators will likely be preoccupied longer on healthcare reform, which could complicate Obama's efforts to get legislation passed just as the world prepares for a December summit in Copenhagen on global warming.

It (the climate bill) is not going to get squeezed out of the Senate's schedule, predicted Daniel Weiss, director of climate strategy for the Center for American Progress.

The biggest problem is that some of the most important players in the clean energy debate will be distracted, he said on Thursday.

The U.S. House of Representatives has narrowly approved legislation to reduce industrial emissions of carbon dioxide by 17 percent by 2020 and 83 percent by 2050, from 2005 levels. Senators are still writing their version of a bill that Democrats promise will be similar to the House version.

Besides cutting greenhouse gas emissions, the initiative would move U.S. companies to cleaner energy sources and potentially force major changes in the way Americans generate electricity.

KEY SENATORS

Senate Finance Committee Chairman Max Baucus, a Democrat who has been devoting nearly all his attention lately to the details of healthcare reform, also has a large stake in crafting the climate bill.

His committee is expected to consider whether border taxes should be imposed on energy-intensive manufactured goods imported from foreign countries that don't embrace controls on carbon emissions, which are blamed for global warming.

Representing the coal-producing state of Montana, Baucus also wants to make sure there are built-in protections for that industry. Coal burned by electric utilities is a major contributor to greenhouse gas emissions.

Democratic Senator John Kerry, a leading advocate of climate change legislation and head of the Foreign Relations Committee that also will write part of the bill, serves on the healthcare-writing Finance Committee as well.

And so does Democratic Senator Jeff Bingaman, who chairs the Energy and Natural Resources Committee that will have a major role in the climate debate.

Even before healthcare reform hit delays, many senators were skeptical there would be time this year to pass a climate bill before December's Copenhagen meeting, which hopes to nail down new long-term targets for global reductions in carbon dioxide emissions.

(Editing by Eric Beech)