U.S. President Barack Obama will start reversing former President George W. Bush''s climate change policies on Monday with steps to raise fuel efficiency standards and grant states authority to limit greenhouse gas emissions from cars.

An administration official said late on Sunday that Obama, who took office last week, would direct the Environmental Protection Agency to reconsider a request by California to impose its own strict limits on automobile carbon dioxide emissions.

The request was denied under the Bush administration, prompting California and several other states to sue. The official said a final decision by the EPA would likely take several months.

Another official familiar with the policy shift said Obama would instruct the EPA to approve the waiver allowing California to impose the rules. The state asked the new administration last week to reconsider its request.

If the EPA reverses the previous ruling, more than 12 U.S. states could proceed with plans to impose strict carbon dioxide limits.

California wants to reduce the emissions by 30 percent by 2016 -- the most ambitious federal or state effort to address global warming.

Ailing carmakers, which have accelerated efforts to build more environmentally friendly vehicles, have fought the California statute, but braced for a policy reversal once Obama won the November 4 election.

Obama promised on the campaign trail to take aggressive action to fight global warming and reduce emissions blamed for heating the earth. He is scheduled to deliver remarks on jobs, energy independence and climate change in the East Room of the White House on Monday.