The arrangement under which racetrack owner and prominent developer Mark Vogel will relinquish control of his two harness racing tracks does not specify when, if ever, he can regain authority, a source who has seen the agreement said yesterday.

Meanwhile, one of Vogel's prime pieces of real estate in Prince George's County, an 872-acre parcel of the proposed Villages of Belmont, was scheduled for foreclosure sale at 10 a.m. today on the steps of the courthouse in Upper Marlboro. However, an attorney representing Vogel and Leeland Road Associates Limited Partnership, which owns the property, said yesterday that the group would file for bankruptcy this morning if it could not find additional revenue sources in time to satisfy the mortgage holder and stop the sale.

The plan to remove Vogel, formulated by the Maryland Racing Commission and verbally accepted by Vogel -- arrested for cocaine possession Sept. 13 -- strips him of operational and financial control of Rosecroft Raceway in Oxon Hill and Delmarva Downs, near Ocean City, the state's only harness tracks. According to sources, that authority will be delegated to Jim Murphy, president and general manager of the tracks.

The move was designed to separate the tracks from Vogel's other holdings. Questions about Rosecroft's financial stability, driven by allegations that Vogel pledged some $2 million in track funds for nonracing purposes, surfaced before Vogel was arrested, according to state racing officials.

Vogel had not signed the agreement as of last night, according to his lawyer, Paul Mark Sandler. Ken Schertle, executive director of the Maryland Racing Commission, said he expected to have the signature before the joint legislative subcommittee on racing meets Thursday in Annapolis to discuss business affairs of both tracks. Racing commission members will attend the meeting; Sandler said neither he nor Vogel will appear.

The Department of Licensing and Regulation said details of the contract between Vogel and the racing commission would not be released before the hearing. However, one source who read the plan said it provides for Vogel's reinstatement when the racing commission and he "mutually agree."

Sen. James C. Simpson (D-Charles), a member of the subcommittee, said the alleged channeling of track assets has generated "the biggest concern that has faced the {harness} racing industry in Maryland in years" and potentially could jeopardize its future now that Freestate Raceway has been closed permanently and no alternative sites exist.

"Any time you have one individual controlling all the racing in this state, it can be a real problem," Simpson said. "If he's pledged {racetrack} assets that are tied up in foreclosure, there might not be any options available. It's not like moving a game from RFK Stadium to Memorial Stadium. There's nowhere else to go."

The arrangement means Murphy is likely to remain at Rosecroft until the tracks regain financial stability or are sold. Murphy replaced Bill Miller as Vogel's chief executive in January on the condition that Vogel purchase Atlantic City Race Course, a thoroughbred track of which Murphy is president and general manager. Vogel has met repeated delays in his prospective $17 million purchase of Atlantic City, and New Jersey racing officials indicated the deal has been threatened by his inability to raise funds by a Sept. 30 deadline.

Murphy said he has no intention of leaving Rosecroft. "There is no question in my mind that if I were to pull out it would destabilize the situation even more," he said.

Faced with mounting bank debt, a foreclosure on one of his real estate projects and a $600,000 tax lien, Vogel might be positioning himself to sell Rosecroft and Delmarva, sources have indicated. Under present market conditions, however, the tracks likely would bring little more than $12 million, roughly the amount of debt against them. Vogel assumed $6 million in long-term debt when he bought Rosecroft in December 1987.

Murphy restated that Vogel's detachment from track affairs will pose no disruption because the owner has had little participation in everyday affairs of either track.

Rosecroft is scheduled to race through Dec. 22. For the rest of the year, Delmarva will receive Rosecroft's simulcasts.

His racetracks beset by turmoil, Vogel faces other problems. A Chapter 11 bankruptcy filing on behalf of Leeland Road Associates automatically would halt the foreclosure sale of the Villages of Belmont, at least temporarily. The bankruptcy filing would pertain only to Leeland Road Associates, whose sole property is the Villages of Belmont, attorneys said.

"There are some possibilities of refinancing the property," said Ira C. Wolpert, an attorney for Vogel. "If not, we will have to file for bankruptcy at 9 a.m."

The 872-acre tract went into foreclosure after Vogel failed to make a semi-annual $219,000 interest payment in August on a $4.3 million note held by the estate of Leo Storch, said Richard Lehmann, an attorney representing the Storch estate. Vogel purchased the property in 1987 from the Storch family, who agreed to finance $4.3 million of the purchase, said Lehmann.

Staff writer Marilyn W. Thompson contributed to this report.