ALBANY — A casino entrepreneur who was one of Governor Spitzer’s largest political donors and who provided Mr. Spitzer with discounted trips on a private jet during the gubernatorial campaign is positioned to win a video gambling contract with the state worth hundreds of millions of dollars.

Excelsior Racing Associates, one of whose main investors is Richard Fields — who donated $200,000 to the Spitzer campaign through his various limited liability companies — has emerged as the leading candidate to take over video lottery gambling operations at one or more horse racing tracks in the state.

The emergence of Excelsior as the leading contender to run the lucrative casinos is threatening to place Mr. Spitzer, who has vowed to restore integrity to state government, in an awkward position.

Mr. Spitzer is aggressively pushing lawmakers to rein in campaign finance rules, urging them to agree to slash contribution limits across the board and to ban donations from limited liability companies, which have been used by contributors to circumvent individual donor limits.

Mr. Fields was one of the top LLC contributors last year, giving about four times the individual limit to the Spitzer campaign through his various entities.

Earlier this year, the Spitzer administration indicated that despite the contributions, Mr. Fields was unlikely to find the state accommodating.

“Time will tell whether Fields means anything to us. I think you’re going to find out pretty quick the answer is no,” an administration official who asked not to be identified told The New York Sun in February. “He was a means to get from point A to point B at one point during the campaign. And later on, he wanted to be helpful in a campaign context.”

Said the official: “I am positive we won’t be talking about Fields in three months or six weeks.”

A spokesman for Mr. Spitzer said yesterday the administration is not inclined to favor Excelsior but is left with few options because the other two companies bidding for the franchise have indicated they are not interested in a partnership with the racing association.

This month, the administration decided that rather than prolonging a legal battle with the New York Racing Association over land claims — the association has asked a federal bankruptcy judge to block the transfer of the franchise, claiming it owns the land on which the tracks sit — it would seek to allow NYRA to continue operating the tracks under a new leadership, with a separate private entity in charge of video gambling at Aqueduct and possibly Belmont. The Assembly and the Senate, which have the power to approve the awarding of the franchise, are considering the arrangement.

“We are not pushing anybody. Obviously, we would have preferred that there would be other bidders,” the spokesman, Darren Dopp, said. “At this point, there doesn’t appear to be other bidders interested in this particular arrangement.”

Excelsior’s strong standing has provoked outcry from one of its competitors, Empire Racing Associates, which is alleging that the for-profit venture colluded with the New York Racing Association to split up operations in an arrangement that would give the association control over racing and one of the bidders control over gaming.

NYRA, a nonprofit entity, has held the franchise to operate Saratoga Race Course, Belmont Park, and Aqueduct since 1955, losing millions of dollars and facing charges of financial mismanagement. The franchise is set to expire on December 31.

A spokeswoman for Excelsior, Katie Burke, denied the charges, saying, “The allegations of collusion are unequivocally and patently false. The meetings with NYRA never transpired nor did the conversations they allege.”

Empire is denying that it is not interested in a partnership with the association. “We are interested in any scenario that protects the interest of New York’s horsemen,” said David Vermillion, a spokesman for Empire, which is backed by major players in the national horse racing industry.

Mr. Fields’s assistance to the Spitzer campaign emerged as a campaign issue in August when campaign records showed that the then attorney general received discounted trips on a private jet belonging to Mr. Fields that shuttled the candidate to fund-raising stops in Arizona and Ohio. Following federal standards, Mr. Spitzer reimbursed Mr. Fields at a first-class commercial rate that was significantly less expensive than private air transportation.

The state lobbying commission launched an investigation into Mr. Fields to determine if the trips violated lobbying rules. Soon after, Mr. Spitzer, who was never accused of any legal wrongdoing, announced that going forward he would pay for the full cost of such flights.

In January, it emerged that Mr. Spitzer and his wife also flew on private jets belonging to Mr. Fields to attend a July fund-raiser hosted by the developer in Jackson Hole, Wyo. Mr. Spitzer’s January 15 campaign filings showed that the campaign returned more than $100,000 to Mr. Fields to cover expenses that exceeded the maximum amount that each of his companies was allowed to contribute.