Regulator: Oil speculators 'tapping the gas pedal'

"We have a historic high of supply and fairly stable demand. So when you say, 'Why are prices rising?' it gives credence to the issue that speculators may be having a big influence," he said.

Chilton also reiterated his view that the growth of speculative trading helped send oil prices to record highs — the $145 a barrel range — in the summer of 2008.

But Chilton emphasized that speculators are not the main reason why oil prices have recently surged to more than $100 a barrel, the highest price in more than two years.

"I'm not suggesting that they are driving it. Certainly the Middle East and other issues are having some impact, also," he said.

Last year's Wall Street reform law requires regulators to set limits on the size of speculative positions that traders may take in commodities markets.

"We need these position limits in place and we need them soon," Chilton said.