The U.S. petroleum industry, already enjoying record profits from skyrocketing oil and natural-gas prices, lobbied aggressively for the legislation and received billions in tax breaks partly designed to encourage new drilling.

But the industry is unlikely to start sinking new wells based on those incentives alone, projects that require years of development before they add fresh oil and gas to the market, experts said.

"The energy bill is not going to make a meaningful difference in U.S. supplies," said Steve Enger, an analyst with Petrie Parkman, an energy-investment bank in Denver.

The bill, the first overhaul of national energy policy in a more than a decade, was approved by the House of Representatives yesterday; Senate approval is expected today. Bush, a former Texas oilman, has pushed for the energy bill since taking office in 2001 and is expected to sign it.

Some critics said the legislation represents a giveaway to the energy industry.

With crude trading near $60 a barrel, oil companies "don't really need much more encouragement" to launch exploration projects, said Rick Mueller, senior oil analyst at Energy Security Analysis. "Companies already are looking anywhere they can to find additional barrels."

Moreover, the energy legislation won't do much to quench U.S. thirst for oil. Rising demand in the United States — the world's biggest consumer of petroleum — as well as in China, India and elsewhere has been a major factor in keeping global oil markets tight and pump prices high.

"There's very little in the bill, really, to address that," Mueller said.

Even Energy Secretary Sam Bodman cautioned that motorists should not expect a quick decline in gasoline prices.

"There are no magic bullets in this law that will change energy prices in the next day, week or month," Bodman said. "It's going to take a number of months, if not years, to deal with energy prices."

The bill's $11.5 billion in tax breaks over 10 years are not just aimed at generating more oil and gas supplies. They also include the first-ever tax credit for nuclear-power companies and a range of measures to promote conservation and energy efficiency.

However, lawmakers rejected language — opposed by U.S. automakers — that would have required the federal government to adopt tougher fuel-economy standards for sport-utility vehicles and other gas guzzlers and to look for other ways to cut U.S. oil consumption.

Still, the Bush administration hailed the bill as laying the groundwork for energy independence.

"For over four years, the president has called for a national energy strategy for our national and economic security," and getting Congress "to come to an agreement is definitely an achievement," said White House spokeswoman Dana Perino.

Concerns about U.S. energy security on imported oil increased last month when a Chinese oil company jumped into the bidding for Unocal.

The United States, which consumes about 20.7 million barrels of oil a day, depends on imports from Canada, the Middle East and elsewhere for about 58 percent of that oil, according to the Energy Department. That dependence on foreign oil has jumped from about 45 percent a decade ago.

About 30 percent of the 5.4 million barrels of oil produced in the United States each day comes from the waters of the outer-continental shelf. Most of that is in the Gulf of Mexico, although production off the coasts of Alaska and California is also included.

The energy bill's oil-related incentives, which include reduced royalties on oil pumped from under U.S. waters, mainly affect deepwater projects in the Gulf, where companies have stepped up exploration without the promise of additional tax breaks. Production in the Gulf is expected to surge 33 percent, to 2 million barrels a day, by the end of the decade, Mueller said.

The incentives provide "an incremental step" toward boosting exploration in the Gulf, said John Felmy, chief economist of the American Petroleum Institute, the oil industry's trade group in Washington. The measures included in the bill "could be the marginal difference between whether to do it or not," he said.

Russ Roberts, spokesman for Exxon Mobil, the largest U.S. oil company, called the bill "an important step toward providing consumers with reliable and affordable energy supplies, while addressing the need for conservation and energy efficiency."

Oil, utility and other energy companies have spent more than $314 million in the past the past 2 ½ years lobbying federal officials on energy-related legislation and other industry concerns, according to PoliticalMoneyLine, which tracks lobbying expenses.

But companies didn't get everything they wanted; at least not yet. For example, a provision that would have opened Alaska's Arctic National Wildlife Refuge to drilling was dropped from the final version. Still, when Congress returns from its August recess, it is expected to vote to open a portion of the refuge to energy exploration.

Critics complained that the oil industry is receiving tax breaks at a time they are enjoying record profits because of the surge in energy prices.

In the last three months of 2004, for instance, Exxon Mobil's profit shot up 27 percent from a year earlier to $8.4 billion, the largest quarterly profit ever for a U.S. public company. The oil giant's full-year profit was a company record $25.3 billion.

"While the energy bill does not decrease dependence on foreign oil, it does increase dependence on federal handouts," said Tom Schatz, president of the Council for Citizens Against Government Waste, a watchdog group.