Maine’s two U.S. senators played key roles in shaping an energy bill passed late Thursday night that would mandate more fuel-efficient cars and funnel hundreds of millions of dollars into research on climate change and alternative energy.

Sens. Olympia Snowe and Susan Collins, both Republicans, joined 63 of their colleagues in voting for an energy bill aimed largely at increasing efficiency, reducing U.S. dependence on foreign oil and developing new energy sources.

Snowe was active in negotiating a compromise that would substantially improve vehicle fuel economy while avoiding a threatened filibuster from lawmakers, primarily within her own party, opposed to the new standards.

“I can tell you it was a close call, and we were relieved and ecstatic,” Snowe said in a telephone interview Friday.

It’s an issue that Snowe has been working on for the last six years with Sen. Dianne Feinstein, a California Democrat. The two senators have been pushing to increase fuel economy standards by 10 mpg over 10 years, which was incorporated into the final Senate bill.

The bill would require manufacturers to achieve an average fuel efficiency of 35 mpg across their fleet by 2020. For the first time, trucks and SUVs would be in the same category as passenger cars, which Snowe also supported.

Snowe called the energy legislation a “landmark” measure that, if enacted by the House, would force domestic auto manufacturers to follow the example of Japanese manufacturers while moving the U.S. toward greater energy independence. She credited the bill’s passage to a combination of factors, including growing public outcry over the price of gasoline and the Democrats’ takeover of Congress.

“I think there was a realization that emerged that it simply doesn’t make sense in the 21st century that we couldn’t compel the domestic manufacturers to become more fuel-efficient … when the foreign manufacturers are outpacing us,” Snowe said.

Collins, meanwhile, authored two items in the energy bill that could benefit climate and alternative energy research programs at the University of Maine.

The bill authorizes $10 million per year for six years for the National Oceanic and Atmospheric Administration’s research programs on what is known as “abrupt climate change.” This area of science studies the history of sudden but dramatic climate shifts – sometimes happening in a decade – and the potential for global warming triggering such abrupt changes.

The second item authorizes $275 million over five years to research programs on developing low-carbon sources of energy, such as fuels made from crops or wood.

“I continue to be extremely proud of the world-renowned research conducted at UMaine’s Climate Change Institute as well as research that is helping to develop alternative sources of energy, such as woody biomass,” Collins said in a statement. “UMaine will no doubt continue to play a pivotal role in the future of these crucial environmental and energy issues.”