Contributors who advocate legalization of slot machines in Maryland gave more than a half-million dollars to state campaigns over the past four years, using loopholes in the campaign finance law to exceed contribution limits, according to a study released yesterday.

Gov. Robert L. Ehrlich Jr. (R), who last week introduced legislation to legalize slot machines at four of the state's horse-racing tracks, was the top recipient. He and his running mate, Michael S. Steele, received more than $121,000, according to the study.

"The study shows we are defenseless against organized gambling, who are trying to turn the state capital into a company town," said James Browning, executive director of Common Cause Maryland, the campaign finance reform group that wrote the study.

Ehrlich spokeswoman Sharesse DeLeaver said the campaign funding had no influence on the governor, who as a candidate last year promised to push for legalized slot machines.

"Keep in mind that Governor Ehrlich was long a proponent of slots," DeLeaver said.

The Common Cause study found that the biggest contributor was William Rickman, who owns Ocean Downs, a standardbred track near Ocean City, and Delaware Park, a track near Wilmington, Del., where slots are legal. Rickman has plans to build a racetrack in Cumberland, one of the four tracks where Ehrlich wants to make slot machine gambling legal.

Maryland law places a limit of $10,000 per election cycle on contributions by an individual or business.

Through his various businesses, partnerships and family members, Rickman gave $183,565 over the last four-year election cycle, according to the study.

The study also determined that the Maryland Jockey Club, which operates the Pimlico and Laurel Park tracks, contributed $42,515 to candidates. The Jockey Club, recently purchased by Magna Entertainment Corp., was owned by the DeFrancis family, longtime Marylanders who retain the right to reap some of the proceeds should slot machine gambling become legal. Pimlico and Laurel Park would get slot machines under Ehrlich's bill.

While Ehrlich was the top recipient, slates and party committees that raise money to keep Democrats in control of the General Assembly received $69,435.

Also among the top 12 recipients were key members of the Democratic legislative leadership team, including the previous House speaker, Casper R. Taylor Jr. (Allegany), who lost his seat in an upset, and Del. Sheila Ellis Hixson (Montgomery), who as chairman of the House Ways and Means Committee is expected to play a key role in the slots legislation.

The study found that gambling interests also contributed $66,915 to the defeated Democratic gubernatorial ticket headed by Kathleen Kennedy Townsend, who opposed legalization of slot machines. Baltimore Mayor Martin O'Malley and Montgomery County Executive Douglas M. Duncan, two Democrats who considered running for governor in 2002 and are mentioned as potential candidates in 2006, also made the top 12 list.

Senate President Thomas V. Mike Miller Jr. (D-Prince George's) received nearly $10,000 from gambling interests, and campaign committees with which he is affiliated received an additional $28,500, the report said. Miller, who supports legalization of slots, said yesterday that he was open to legislation that would bar candidates and parties from receiving campaign contributions from gambling interests.

Ehrlich has said he is interested in such a prohibition, and state GOP Chairman John Kane said yesterday that he is not opposed.

"As long as it's a balanced and fair bill, I don't have a problem with it," Kane said. "Certainly, gaming interests are not apple pie. . . . There does exist the potential for corruption."

Courts in New Jersey and Louisiana have upheld bans on gambling contributions similar to the one proposed in Maryland. The U.S. Supreme Court declined to hear an appeal in the New Jersey case and is expected to decide this month whether to hear the Louisiana case.

David O. Stewart, a lawyer with the Washington-based firm of Ropes & Gray who represents the Casino Association of Louisiana, contends that the laws unfairly single out an industry.

"This creates the potential for legislatures to punish political enemies and rivals," he said. "And it's a way for legislators to say we're going to have gambling but we'll be pure. They are running for cover at the expense of the rights of the business they are setting up."