The dealings of gambling interests with the former Republican state attorney general, Dennis Vacco, and the current Democratic state Assembly speaker, Sheldon Silver, brought big fines yesterday from the state Lobbying Commission.

Mr. Vacco’s lobbying firm, Crane & Vacco LLC, was fined a maximum $50,000 for signing a contract in 2004 that guaranteed the firm $5.5 million if it won the Seneca-Cayuga Tribe of Oklahoma approval to open a casino in New York. The deal was signed with Thomas Wilmot, a wealthy Rochester businessman seeking a casino deal in the Finger Lakes area with the tribe.

The Lobbying Commission’s executive director, David Grandeau, said he believed the arrangement was a misdemeanor that could come before a state prosecutor. By law, lobbyists cannot agree to deals in which payments are based on the success of a project or legislation. The commission has referred other cases for prosecution to the state attorney general’s office. But the spokesman for the politically appointed commission, Kris Thompson, wouldn’t say if the Vacco case was recommended for criminal prosecution.

A lawyer representing Crane & Vacco, James Featherstonhaugh, denied any crime was committed. He said since the Legislature decided to allow casinos to be built in the Catskills in 2001,no lobbying was being conducted.

He said the firm was only being paid to negotiate a casino compact with the state and added that Crane & Vacco only settled the case to “get on with business” and put the matter to rest.

Separately, Caesars Entertainment, now owned by Las Vegas-based Harrah’s Entertainment Incorporated, was fined $25,000 for providing a discounted room to Mr. Silver while casino issues were debated in Albany. The casino operator sought to become a partner in an American Indian-sponsored casino in the Catskill Mountains of New York. The fine is one-fifth of the maximum penalty.

In September 2004, Mr. Silver testified for nearly three hours to the state Lobbying Commission’s staff. Mr. Silver was billed $109 for a suite at Caesars Entertainment’s Paris Las Vegas in 2002. The room was advertised as renting for as much as $1,500 a night.

Records supplied to the Lobbying Commission showed a $50 tip was paid to a caterer for having “dinner flown in” for the Assembly speaker and his guest. The records did not indicate the cost of the meal or who provided the tip, which Mr. Silver said he did not pay.

Mr. Silver said the trip was made in the post-September 11, 2001, period when Las Vegas and other tourist destinations were discounting travel costs and hotel rooms to generate business. A spokesman for Caesars Entertainment previously said the cost of the suite varies and that it’s generally used by high-roller gamblers at the hotel’s casino. Mr. Silver has not been accused of any wrongdoing in the case, a spokeswoman, Eileen Larrabee, said. A spokesman for Harrah’s did not return a call for comment.

In another case, KeySpan Energy and Citicorp each agreed to pay $15,000 fines to settle charges they violated the $75 state gift ban by giving out Red Sox tickets and hosting events for lawmakers at the Democratic National Convention in Boston last year.

Also, the energy company Dominion Resources Services Incorporated and insurance giant AIG agreed to pay for parties public officials attended that cost more than $75 a person.