Gov. Robert L. Ehrlich Jr.'s latest plan to legalize slot machines in Maryland has produced a wave of intense lobbying in the General Assembly as horse owners, school advocates, local governments and casino companies all try to secure a larger share of the gambling jackpot -- and are threatening to kill the bill if they don't.

Only racetrack owners seem happy with the plan Ehrlich (R) announced last week, which would give them nearly half of the proceeds from 11,500 slot machines at four tracks. Horse owners complain that only a tiny portion is dedicated for racing purses. Some lawmakers are angry that Ehrlich cut the percentage of slots revenue earmarked for public schools by a third. Local governments are miffed that they wouldn't get more.

Casino interests also are displeased that Ehrlich shut them out of his bill altogether. But they have not given up their efforts to bring full-blown gambling to Maryland. One of their allies, U.S. Rep. Albert R. Wynn (D-Md.), is passing around a study in Annapolis that touts the economic benefits of legalizing slots at racetracks as well as casinos at the planned National Harbor development along the Potomac River and the Inner Harbor in Baltimore.

Legislators acknowledged that they are feeling pressured to change the formula that dictates how an estimated $1.5 billion a year in slots revenue would divided.

"All those numbers now are moving targets," said Sen. Ulysses Currie (D-Prince George's), chairman of the Senate budget committee that will vote on Ehrlich's bill. "I'm not sure how far they'll move, but they'll change."

Racetrack owners were the big winners under Ehrlich's reworked bill, his second stab at a plan to legalize slots.

Ehrlich wants to authorize the owners of three tracks -- Pimlico in Baltimore, Laurel Park in Anne Arundel County and Rosecroft Raceway in Oxon Hill -- to operate 10,500 slot machines combined. He also would grant 1,000 slots to a racetrack that is to be built in Allegany County.

In exchange for $120 million in licensing fees, the three major tracks would receive 44 percent of the proceeds from slots. Over the licenses' 20-year lifetime, Ehrlich projects that the track owners would bring in more than $6 billion in gross profits and also would be reimbursed $7 billion in operating expenses.

Some lawmakers are upset that the tracks would receive more money than public schools -- which would get 42 percent of the revenue under Ehrlich's plan.

Sen. Gloria G. Lawlah (D-Prince George's), a member of the Senate budget committee, said she would push to give more money to public education and local governments.

"We're going to amend the governor's bill," Lawlah said flatly. "We're going to put some new numbers in."

Some black lawmakers also are unhappy that Ehrlich did not include a provision that would require the racetracks to cut deals with minority investors, a high priority of the Maryland Black Legislative Caucus.

Chip DiPaula Jr., Ehrlich's budget secretary, played down the opposition.

"Everybody wants more," he said. "This is a huge deal. It should come as no surprise that all the stakeholders would want to maximize their benefit."

DiPaula said the administration relied on a private consultant to shape its slots bill. The consultant, KPMG LLC, was paid $250 an hour and produced several written reports that form the backbone of Ehrlich's slots plan.

The Washington Post has sought the records under the Maryland Public Information Act, but DiPaula is withholding the documents and would not say when he might release them. The Ehrlich administration also has withheld records that would describe how much the governor and his staff relied on the horse industry to shape its slots plan.

It is unclear when the General Assembly will make a decision on slots; Ehrlich has not submitted the fine print of his plan. Time is running short, however -- the legislature is scheduled to adjourn April 7.

The House of Delegates is considering a bill that would create a study commission on gambling and possibly delay slots for a year, so Ehrlich is counting on Senate leaders to push his plan.

As a result, groups with a stake in slots are training their sights on the Senate as they make their case for a greater share of the anticipated gambling windfall.

Ehrlich has argued that slots are necessary to save the state's ailing horse racing industry, but the Maryland Thoroughbred Horsemen's Association is peeved that the governor is dedicating just 3.6 percent of slots revenue, or about $52 million a year, for racing purses.

"This is woefully insufficient to truly save racing," said Wayne Wright, the group's executive secretary. "Horsemen have waited for eight years for this opportunity. And what they envisioned . . . was enhanced purses that would put us back into the top tier of racing."

Local governments also want more than the $55 million they would receive under Ehrlich's plan. They are asking lawmakers to double or triple their share to offset the costs of increased traffic and other demands on local services that would result from slots.

"There's a lot of serious fuzzy math going on," said Nancy Lineman, a spokeswoman for Prince George's County Executive Jack B. Johnson (D). "Local jurisdictions aren't getting enough of the pie."