Washington, D.C. ? A plan to increase fuel efficiency standards to an average of 35 miles per gallon by 2020 won approval from a Senate panel Tuesday in a vote closely watched by automakers and environmental groups.

The Senate Commerce, Science and Transportation Committee approved the measure, which would raise the nationwide fleet fuel economy average by about 40 percent from current levels of 25 mpg for cars and trucks. The bill, approved on a voice vote, would also increase standards by 4 percent a year from 2020 through 2030.

“This is not a perfect bill, but I think we have reached a stage where most parties would say this is fair,” said Sen. Daniel Inouye, D-Hawaii, the committee chairman.

He said the bill would be considered before the full Senate in June.

This was lawmakers’ first step in demanding more efficient vehicles from automakers amid concerns about global warming and the nation’s dependence on imported oil. Gasoline prices have leapt in recent weeks to a record nationwide average of $3.07 a gallon, or nearly 20 cents higher than two weeks earlier, according to the Lundberg Survey.