WASHINGTON — Wall Street banks and other large financial institutions have begun putting intense pressure on Congress to hold off on legislation that would curtail their highly profitable trading in oil contracts — an activity increasingly blamed by lawmakers for driving up prices to record levels.

Representatives of Goldman Sachs and Morgan Stanley, along with the trade associations for hedge funds and other financial groups, have lobbied the offices of key legislators, briefed senior staffers on committees that oversee pivotal parts of the energy markets and distributed research materials explaining their view about oil and how it's traded.

In a pair of lengthy and sometimes testy, closed-door sessions in the Senate last week, executives from Goldman Sachs and Morgan Stanley, two of Wall Street's largest investment banks, made the case that their multibillion-dollar investments in energy contracts have not led to higher oil prices. Rather, they told Democratic staff members of the Energy and Natural Resources Committee, a panel responsible for energy policy, that the trades allow international markets to operate efficiently and that the run-up in oil prices results not from speculation but from actual imbalances of supply and demand.

But the executives were met with skepticism and occasional hostility. "Spare us your lecture about supply and demand," one of the Democratic aides said, abruptly cutting off one of the executives, according to a staff member in the room.

Another aide at the meetings warned the executives that no matter what arguments they muster, it would be hard to prevent Congress from acting. Referring to a vote earlier this year to impose new mileage standards on automobile makers, the aide said, "At 90 bucks a barrel, Congress rolled the autos for the first time in 30 years — is it too much to think that Congress will impose more restrictions on you if oil goes to $150 dollars a barrel?"

Goldman and Morgan declined to comment about the meetings.

Separately, lobbyists for the International Swaps and Derivatives Association and for other financial entities such as hedge funds roamed through congressional office buildings this month and, in the Senate, left behind short policy statements that defended the current state of regulation. "Blaming speculation for the increase in energy prices is to confuse causation and correlation," one of the documents said.

A second document, or "talker," asserted: "Congress and regulators have acted to strengthen oversight of the energy markets. Give the new authorities time to work."

But time is running short. The Commodity Futures Trading Commission, the federal agency that regulates oil trading, has drawn the increasing ire of lawmakers for exempting financial firms from rules that limit speculative buying, a prerogative usually reserved for airlines and trucking companies that need to lock in future fuel costs. The CFTC has also waived regulations on U.S. investors who trade commodities on some overseas markets, allowing them to accumulate large quantities of the future oil supply by making purchases on lightly regulated foreign exchanges.

Under pressure from lawmakers, the CFTC and its British counterpart agreed Tuesday to impose new limits on the trading of the United States' benchmark oil contract on a London exchange. Such trading of West Texas Intermediate oil contracts has been occurring beyond the purview of U.S. regulators on the London platform, the Intercontinental Exchange.

The move did not go far enough to satisfy some Democrats who criticized the CFTC for abdicating the job of policing overseas oil traders to the Intercontinental Exchange.

Until recently, Congress had been reluctant to intervene in the energy futures markets, and the lobbying by financial entities has been a major reason. "We have known since 2001 that there were problems here, but we've run up against people on Wall Street who don't want to be helpful in policing the market," said Sen. Maria Cantwell, D-Wash., one of several lawmakers frustrated by the effectiveness of the financial lobby.

A growing number of members of Congress have reacted to public outrage over skyrocketing gasoline prices by introducing at least eight bills that restrict the ability of financial companies to buy futures contracts, disclose more about those investments or stiffen federal oversight of energy trades. Other legislation is in the works, congressional aides said.