Obama makes a shift, says tap oil reserves

By Caren Bohan

LANSING, Mich. (Reuters) - Barack Obama proposed tapping the strategic oil reserve on Monday to help lower gas prices, reversing an earlier stance, and called rival John McCain a tool of big oil companies as rising energy costs took center stage in the U.S. presidential campaign.

Obama, celebrating his 47th birthday, unveiled a package of steps designed to end U.S. reliance on oil imports from the Middle East and Venezuela within 10 years, including tax credits for buyers of fuel-efficient hybrid cars.

In a speech in Michigan, a battleground in November's White House election and home to the struggling U.S. auto industry, he proposed releasing 70 million barrels of light oil, easier to refine into gasoline, from the emergency U.S. stockpile.

The Democratic senator from Illinois said the light oil could be replaced later with heavier crude in a swap designed to bring quick relief from high gasoline prices.

"We have to make a serious, nationwide commitment to developing new sources of energy and we have to do it right away," Obama said in Lansing, Michigan.

McCain fired back in Pennsylvania, criticizing Obama's opposition to nuclear power and offshore drilling and calling on Congress and Obama to return to Washington from their summer break to try to solve the country's energy challenges.

"Anybody who says that we can achieve energy independence without using and increasing these existing energy resources either doesn't have the experience to meet the challenges we face or isn't giving the American people straight talk," McCain said in Lafayette Hill, a suburb of Philadelphia.

The Obama campaign responded with a challenge.