Maryland developer and racetrack owner Mark R. Vogel pleaded guilty yesterday to cocaine possession in Fairfax County Circuit Court and was placed on probation.

Despite the plea in state court, Vogel remains a target of a federal probe into allegations of drug abuse among a circle of developers and lawyers, federal law enforcement sources said.

Vogel's guilty plea yesterday will not affect the federal investigation, the sources said.

Under a plea agreement reached with Fairfax County, the charge against Vogel, 42, will be dismissed if he does not commit another criminal offense before Nov. 29, 1991, the prosecutor and his attorneys said. Fairfax Circuit Court Judge F. Bruce Bach agreed to continue the case and not enter a finding of guilt for a year.

Vogel, who built a $1 billion real estate empire in less than a decade, was charged with drug possession Sept. 13 after agents from the U.S. Drug Enforcement Administration and Fairfax County police found about 4 grams of cocaine worth an estimated $400 in his 1990 Corvette after stopping his car on Georgetown Pike.

"He has entered a guilty plea, but he can honestly say that he has not been convicted of a felony," said Plato Cacheris, an attorney for Vogel. "If he behaves himself until Nov. 29, 1991, the case is totally off the books."

Cacheris said that cooperation with law enforcement authorities was not a condition of the plea agreement and that Vogel is not providing information to either state or federal investigators.

Mark C. Simmons, an assistant commonwealth's attorney for Fairfax, characterized the plea agreement as routine and said that it is a type frequently used with first-time drug offenders. Possession of any amount of cocaine in Virginia is a felony.

"He is not going to be sentenced to anything more or less because he is wealthy," Simmons said. "He was treated exactly {as if} he had been a teenager."

Vogel, whose real estate holdings stretch from Northern Virginia to the Eastern Shore of Maryland and include Maryland's two harness racing tracks, has encountered financial problems since his arrest, including filing for protection from creditors on one project and several foreclosures. In recent weeks, lenders have sued him, seeking payment of more than $1.3 million in delinquent debts on projects in Prince George's County and rural Virginia.

Vogel also announced plans to sell Rosecroft Raceway in Oxon Hill and Delmarva Downs near Ocean City, Md., for $20 million to $25 million after state racing commissioners asked that he remove himself from the management of the tracks. Vogel said he hoped the sales would yield profits of $15 million, which he said would save his troubled real estate ventures.

Ken Shirdell, executive director of the State Racing Commission, said yesterday he is unaware of any formal offers for the tracks. He also said the terms of Vogel's guilty plea will be reviewed by the commission, which has the authority to revoke the tracks' operating licenses.

Vogel will be required to take regular drug tests as part of his probation, Simmons said. A positive drug test could be grounds for revoking the probation, in which case Vogel could face a prison sentence of one to 10 years, his attorneys said.

Vogel has no immediate plans to enroll in a drug treatment program, his attorneys said. He decided to plead guilty because he wants to "put the whole sorry episode behind him," his attorney Paul Mark Sandler said.

The guilty plea came a week before Vogel's case was to go to a grand jury.

Vogel told investigators on Sept. 13 that he "knew he had a cocaine problem, but that cocaine is a very addictive drug," according to court papers. The developer also told investigators that he had received treatment for a drug problem, according to the court documents.

After Vogel's arrest, federal authorities seized his corporate helicopter, alleging in an affidavit that the developer and his friends had transported small amounts of cocaine aboard the craft for personal use on trips to Atlantic City. The seizure is not affected by Vogel's plea on the state charge.

Cacheris said that federal investigators have questioned Vogel about local politicians, but that Vogel knows nothing about drug use or corruption among local officials.

"They have asked him to give up politicians, and he doesn't know anything," Cacheris said. "They haven't mentioned any names, and Vogel doesn't know any to tell them. They've said, 'You tell us,' and we don't have anything to tell them."

Vogel told investigators that on the night of his arrest, he was on the way to the home of Carter Vincent Boehm on Georgetown Pike to use the cocaine, which was found in four packages in his car, according to court papers. Boehm, a Northern Virginia real estate broker, dined with Vogel that evening. DEA agents followed Vogel from the Prime Rib Restaurant in the District to the Roberta, an apartment building in the 5400 block of Connecticut Avenue NW, where he obtained the cocaine from a friend, sources said.

The Roberta is owned in part by the estate of Robert A. Podrog, a prominent Washington real estate operator and Vogel friend who died three years ago while on vacation in Mexico. Investigators have questioned several Vogel employees and friends about alleged drug use at the Roberta and with Podrog, law enforcement and other sources said.

Franklin Paulson, the executor of Podrog's estate and a principal in the partnership that owns the Roberta, did not return numerous telephone calls over the last month. Podrog's widow, Judith, also did not respond to requests for an interview.

Podrog, whose estate was valued at $10 million to $12 million, was a longtime friend and occasional business partner of Vogel's. Podrog had invested in Vogel's Fishing Creek Farms, a planned subdivision on the South River in Annapolis, and in his now-defunct Georgetown champagne bar, Flutes, according to court papers.

Staff writers DeNeen L. Brown, Patricia Davis and Veronica T. Jennings contributed to this report.