IMPEACH BUSH

As Congress debates how to curtail the role of speculators and rein in rising oil prices, a U.S. government task force said Tuesday that it had so far found no evidence that those investors are systematically pushing up the cost of energy.

Instead, in an interim report made public on Tuesday, the task force said that its research "does not support the hypothesis that the activity of these groups is driving prices higher."

The preliminary study concluded that the rise in oil prices over the last five years was "largely due" to fundamental factors like rapidly rising consumption and sluggish growth in energy supplies worldwide.

The analysis was spearheaded by the Commodity Futures Trading Commission with help from six other agencies, including the Federal Reserve and the Treasury.

It offers the government's most authoritative view to date on whether investors, using specialized instruments known as index funds and commodity swaps, have contributed to the sharp run-up in oil prices since 2002.

The issue has been hotly debated as oil surged above $140 a barrel and gasoline rose above $4 a gallon, prompting consumer groups to put fierce pressure on lawmakers and regulators.

Congress has held dozens of hearings since January to explore proposals that range from expanding offshore drilling to expelling institutional investors from the commodity markets.

But the notion with the most political traction so far is a proposal from the Senate Democratic leadership that would restrict speculators' role in futures markets, apply those restrictions to any foreign exchange open to traders in the United States, and extend the CFTC's authority to cover swaps trading that does not occur on public exchanges.

In debate on that bill this week, its supporters have repeatedly predicted that reducing the growing role of speculators would allow energy prices to fall.

In its report, the federal task force acknowledged that investors had flocked to the energy futures markets in recent years, attracted by high returns. But the task force said that a review of both public and non-public data shows that speculators could not be fairly blamed for rising prices.

For example, swap dealers, who privately offer investors a future return linked to commodity markets, were roughly balanced between purchases and sales of energy futures contracts. And in the first five months of 2008, more of these swap positions were selling than buying. In that same period, oil prices rose 28 percent.

The report's key finding was that speculative investors more often changed their positions after prices had moved, not before.

That suggests that these traders "are responding to new information — just as one would expect in an efficiently operating market," the report said.

The task force, led by the CFTC, includes staffers from the departments of Agriculture and Energy, the Treasury, the Federal Reserve, the Federal Trade Commission, and the Securities and Exchange Commission. It will release a complete study in September.

In identifying the drivers of energy prices, the report noted that oil consumption grew 3.9 percent between 2004 and 2007. At the same time, oil supplies lagged that demand, with production growth from nations outside the Organization of the Petroleum Exporting Countries slowing to levels far well below the historic averages.

After a record close of $145.29 a barrel on July 3, oil futures on the New York Mercantile Exchange have been sliding in recent weeks. On Tuesday, oil fell $3.09 to $127.95 a barrel. Average gasoline prices have also been declining recently, from a record of $4.11 a gallon on July 17 to $4.05 a gallon on Tuesday.