WASHINGTON — With gas prices near $3 a gallon, Sen. Maria Cantwell, D-Wash., yesterday called for a Senate investigation into allegations that oil companies are gouging customers at the pumps.

The request came a day after Cantwell introduced anti-gas-gouging legislation that calls for federal fines and criminal penalties for price gougers. So far, 23 senators have signed onto the bill, including Democratic Sens. Ron Wyden of Oregon, Barbara Boxer of California and Hillary Rodham Clinton of New York.

"We have heard gas-station owners complaining that the big oil companies ordered them to raise prices after Hurricane Katrina and its tragic aftermath," Cantwell said at a Senate commerce committee hearing yesterday.

"Investigating those claims should be the job of federal regulators — and there should be harsh penalties for that kind of behavior, profiteering in the midst of a national tragedy," she said.

At the hearing, Bob Slaughter, president of the National Petrochemical and Refiners Association, disputed claims of widespread gas price gouging now or in the past.

"More than two dozen federal and state investigations over the last several decades have found no evidence of wrongdoing or illegal activity on our industry's part," Slaughter said.

Oil companies blame rising energy prices on increased demand coupled with limited supply. Hurricane Katrina damaged oil-pumping rigs and refineries in the Gulf.

Gas prices in Washington have hovered at about $2.90 per gallon, about 12 cents more than the national average, the Energy Information Administration says.

Earlier this week, Gov. Christine Gregoire signed a letter with seven other governors asking President Bush to investigate the more than 26,000 price-gouging complaints made to the Energy Department since the end of August.

"There's no apparent reason why there's been an increase in prices," said Gregoire spokeswoman Carole Andrews. "The governor wants to know what's going on."

Twenty-eight states have anti-gouging laws on the books, but not Washington. Cantwell's proposal is one of four similar bills on gas price gouging recently introduced in the Senate, and there are several others now in the House.

Among other things, Cantwell's legislation would give the president authority to declare a national energy emergency. The Federal Trade Commission (FTC) would have more authority to investigate and prosecute gouging, and those found guilty of the practice could face civil fines and up to five years in jail.

The FTC has been criticized for not doing a thorough job of investigating previous claims of price gouging, particularly on the West Coast.

But John Seesel, associate general counsel for energy at the FTC, told committee members that the agency has launched an investigation of recent price-gouging reports.