The new chairman of the Federal Trade Commission wants the agency to play a more active role in the national campaign against obesity.

"I am pushing for us to come up with a game plan on where we can fit in," Deborah P. Majoras said yesterday during her first interview since she took office last month.

While the agency already goes after misleading claims made in ads for food and diet programs, Majoras said she wants the FTC to do more to educate consumers, including working with the Food and Drug Administration to update labeling requirements.

"Not only are we in favor of banning the deceptive stuff, but we want information to be on the label so people know what they're eating and can make their decisions," she said. "Studies have shown that people will actually read nutrition information on labels."

Majoras, 41, succeeded Timothy J. Muris, who resigned to return to George Mason University School of Law. She was a deputy assistant attorney general in the Justice Department's antitrust division before entering private practice earlier this year

Under Muris, the agency last year filed comments with the FDA, urging changes in its nutritional labeling rules to update serving sizes make the amount of calories per serving more prominent and allow comparative calorie claims -- comparing cherry yogurt with cherry pie, for example.

Majoras said she "absolutely embraces the concept that the commission's job is to "stand up for the consumer." But repeatedly she noted that a lot of that advocacy will be through enforcing the FTC laws. "We can educate consumers, but going after the fraudsters . . . is very much a law enforcement aspect."

Thus, she said, she wants to refer more fraud cases to state and federal law enforcement agencies for criminal prosecution. The FTC can file only civil lawsuits.

"We need to strengthen our relationship with criminal enforcers," she said, so violations can be pursued under criminal laws that impose greater penalties than civil action, including jail time. "I want to put these people in jail. I want to use all the tools I have at my disposal to make people pay for the suffering they've caused others."

Majoras was appointed while Congress was in recess, after Sen. Ron Wyden (D-Ore.) blocked her nomination. He charged that the FTC was inadequately policing the oil industry for anti-competitive behavior, which he said led to steep gasoline prices on the West Coast. Majoras can stay at the agency only until the end of 2005 unless the White House resubmits its nomination and the Senate confirms it.

Nonetheless, Majoras said she is "proceeding as though I'm going to be here for a long time. I think there is no other way for me to proceed."

Majoras acknowledged that it may be difficult to win Wyden's support. He complained at her confirmation hearing that her plan to monitor the oil industry was "business as usual."

"I'm not sure that I will convince him," she said. She said is going to designate a "special energy counsel" to coordinate all the agency's initiatives and investigations involving the oil industry. "We can be hyper-vigilant in this industry" to ferret out anticompetitive practices that may drive up gasoline prices, she said. But at "the end of the day, the most important function of the FTC is an enforcement agency and we're only going to enforce against illegal conduct. Right now, I'm not aware of any."

Majoras said she will have to recuse herself on issues that specifically involve ChevronTexaco Corp., one of her clients in private practice. But she said will participate in decisions that affect general oil-industry practices.

On antitrust issues overall, she said she will look for ways the FTC can be more efficient in reviewing mergers and more flexible in imposing remedies for any found to be anti-competitive.

"I believe strongly in the power of markets, in the power of the free market," Majoras said. "In order to equip consumers to function in that marketplace they need full information; they need not to be deceived by misinformation. That is a very powerful part of our missions."

Republican lawyer Deborah P. Majoras succeeded Timothy J. Muris as chairman of the Federal Trade Commission.