Energy Secretary Samuel Bodman on Thursday rejected a call by some members of Congress to release oil from the government's emergency stockpile, saying oil is needed to respond to future supply emergencies and not to influence prices.

Bodman also told a House hearing that he does not believe that rampant market speculation is causing record high oil prices that reached a record $135 a barrel. He said it's a matter of supply and demand that can be traced to essentially flat global production over the last three years.

Rep. Edward Markey, D-Mass., said he did not understand why President Bush is not releasing oil from the Strategic Petroleum Reserve to force down prices. "We have 700 million barrels ... that are ready to be deployed," said Markey.

Bush recently stopped putting oil into the reserve after Congress passed legislation to halt deliveries.

But Bodman said he would not recommend oil being released from the reserve.

The stockpile, now 701 million barrels, "is meant to deal with ... the physical interruption of the flow of oil to our country. We don't have that issue today," he told the House Committee on Global Warming.

Markey said the release of government oil is justified because "we're in an economic crisis" as high oil costs are driving gasoline to $4 a gallon and increasing other costs.

"The American people are being tipped upside down and having money shaken out of their pockets," he told Bodman.

Oil from the Strategic Petroleum Reserve, three underground salt domes in Texas and Louisiana, has been used twice to respond to supply disruptions or the threat of such interruptions: Just before and during the first Gulf War in the early 1990s and in response to the loss of Gulf of Mexico oil after Hurricane Katrina in 2005. President Bill Clinton in 2000 made emergency oil available to relieve prices and Markey said prices then dropped 18 percent.

Meanwhile, the top executives of the country's five largest oil companies made a repeat appearance on Capitol Hill.

After being pummeled by senators over high oil and gasoline prices at a Senate hearing on Wednesday, they were summoned before the House Judiciary Committee on Thursday.

The executives reiterated much of what they had told the senators: The primary cause for high oil prices is tight supplies and growing demand, and that their profits — $36 billion during the first three months of the year — are not excessive given the size of their companies and the need for reinvestment to find more oil.

The executives urged more domestic oil and gas production by opening areas now off limits including large areas of federal offshore waters and a wildlife refuge in Alaska, where billions of barrels of oil are located. "This persistent denial of access is costing American consumers right out of their pocket books," said John Hofmeister, president of Shell Oil Co.

The other executives represented Exxon Mobil Corp., Chevron Corp., ConocoPhillips Co., and BPAmerica Inc.

Bodman, appearing at a separate hearing down the hall from the oilmen. also viewed the problem as essentially one of production not keeping up with demand.

Asked if he believed there was "rampant" speculation driving up oil prices, Bodman replied: "No. I don't."

The biggest problem, he said, is flat oil production and growing demand. Up to 2004, he said the world's producers pumped about 1 million barrels more oil each year, then production increased and so did demand. Demand continued to grow, but beginning in 2005 "there has been no change in global production" and "demand has outstripped supply."

"We have sopped up all the available spare (oil production) capacity in the system," said Bodman.

The world uses about 87 million barrels of oil a day, about a quarter of it in the United States.

Energy experts have acknowledged that most producers have little ability to pump more oil. The exception is Saudi Arabia, which is producing about 9.4 million barrels a day and has the ability to increase that by about 2 million barrels a day but have declined to do so.

Last week, the Saudis said they were boosting production by 300,000 barrels a day in June, but that was only to make up a decline in production by other OPEC countries.