After days of stonewalling, the campaign of gubernatorial candidate Eliot Spitzer yesterday released the names of the airports that the attorney general flew out of on a private jet provided by a gambling figure bidding for the state’s lucrative thoroughbred racing franchise.

In May, Mr. Spitzer, on his way to a series of fund-raisers, flew on a jet provided by Richard Fields from Phoenix Sky Harbor airport to Tucson International airport to Lunken Field airport near Cincinnati, and to La Guardia airport in New York City.

The names of the airports will be important if the state lobbying commission decides to launch an investigation into whether Mr. Fields, a registered lobbyist, violated lobbying regulations by charging Mr. Spitzer and a campaign staffer accompanying him at a first-class commercial rate instead of the actual cost of a chartered flight.

The inquiry was triggered last week by a complaint filed to the commission from Mr. Spitzer’s Republican opponent, John Faso, who is accusing Mr. Fields of under-billing Mr. Spitzer by tens of thousands of dollars. “It’s the worst example of pay-to-play that you can imagine,” Mr. Faso told The New York Sun yesterday.

Mr. Spitzer’s campaign paid a development company owned by Mr. Fields a total of $4,300 for the flights, a figure that the campaign came to by estimating the cost of three one-way first-class trips for two passengers between those cities.

State lobby guidelines, however, require that lobbyists who provide public officials with private or corporate jet transportation to bill officials at the cost of a comparable trip on a chartered plane if the jet is following a route that isn’t serviced by commercial airlines offering first-class seating, according to the executive director of the lobbying commission, David Grandeau, who administers the state’s lobbying guidelines.

“If I can’t get a first-class fare from the originating airport to the terminating airport then you take the value of what a charter would cost,” said Mr. Grandeau, who would not comment on his office’s preliminary inquiry into Mr. Spitzer’s flights.

On May 24 and May 25, Mr. Spitzer took at least two flights on routes where such commercial service isn’t offered, flying to and from Lunken Field airport. The airport exclusively serves private and corporate jets, according to a customer service representative at the airport.

If the commission decides to investigate Mr. Fields and finds that he improperly charged Mr. Spitzer for the flights, Mr. Fields faces a maximum fine of $100,000. Earlier this year, Mr. Fields paid a $9,000 fine to settle an investigation by the lobby commission into whether Mr. Fields undercharged state senator David Paterson, who is Mr. Spitzer’s running-mate, for a flight on a chartered plane from Westchester County Airport to Albany. Mr. Paterson, who had paid $178 for the flight, ending up paying $4,500 after the commission reached a settlement with Mr. Fields, who did not admit to any wrongdoing.

“In the Paterson case, there was no first-class available so he had to pay the value of the charter,” Mr. Grandeau said.

The Paterson case spurred the commission to revise its guidelines for reimbursement of private jet trips. The guidelines state that the “value of private transportation is the first class fare for travel on a comparable common carrier or, if no such fare exists, the pro-rata share of the costs of the transportation.”

Representatives of Mr. Fields and Mr. Spitzer say the candidate was charged a proper amount for the flights and denied that Mr. Fields was in violation of state lobby law or that Mr. Spitzer was in violation of state ethics and election laws, which set forth different standards governing the reimbursement of private transportation.

A lawyer representing Mr. Fields, Ed Wallace, said, “The billing by Fields and the payment by the campaign was entirely consistent with applicable law, including lobby law.”

Mr. Wallace said he strongly disagreed with Mr. Grandeau’s interpretation of state lobby law, insisting that the airports used aren’t relevant. He said lobbyists are allowed to charge a comparable first-class fare for private jet transportation if the plane is taking state public officials to and from cities that are serviced by commercial airports.

A spokeswoman for Mr. Spitzer’s campaign, Christine Anderson, said state law isn’t clear on how the costs of such flights are to be reimbursed, so the campaign followed federal regulations on reimbursement for use of private aircrafts that apply to federal lawmakers and candidates. Federal guidelines allow for reimbursement at first-class rates in trips to cities served by regularly scheduled commercials service.

Asked whether Mr. Spitzer agreed with the federal guideline, Ms. Anderson said, “We have followed the letter of the law on this.”

Lost in the technicalities over the law is the question of appearances. Mr. Spitzer, who has raised tens of millions of more dollars than his opponents have raised, has vowed to end pay-to-play culture in Albany. Mr. Spitzer, in one of his campaign ads, says he follows the “simple rule” of doing the right thing.

The man who provided Mr. Spitzer with rides on a private jet is a developer for the Oneida Nation of Wisconsin, which is seeking state approval to build a casino in the Catskills. He is also part of a group called Excelsior Racing Associates, which is among a number of entities bidding to take over operations of Aqueduct, Belmont Park, and Saratoga racing tracks. Next year’s governor will have a major say over casino development and the selection of a winning bidder with billions of dollars in revenue at stake.

Aside from supplying Mr. Spitzer with a private jet, Mr. Fields has also been an important fundraiser for the Spitzer campaign, raising him hundreds of thousands of dollars.

The federal guidelines that Mr. Spitzer is following have also come under recent scrutiny amid the fallout of the Jack Abramoff lobbying scandal. Critics say the first-class reimbursement policy amounts to subsidized private travel for public officials and several prominent politicians, including Senators Obama and Durbin, have pointedly disavowed the practice.

Mr. Faso said Mr. Spitzer “should give back the money that he raised through this guy to influence his actions…This first-class equivalence thing is totally bogus.”