WORCESTER — A 63-year-old Marlboro man pleaded guilty this morning to running an illegal gambling business that netted $2,000 a day.

Robert Duplessis, of 133 Kosmas St., Marlboro, owned all or part of a sports betting business that also involved several other unidentified people.

The FBI and state police brought a case against Mr. Duplessis, a retired truck driver, last month. Mr. Duplessis’s business was investigated in Marlboro and Milford, according to federal court records.

The operation, which prosecutors said was active from at least 2000 to this past April, also involved an office offshore in Jamaica.

In U.S. District Court this morning, Judge F. Dennis Saylor IV scheduled Mr. Duplessis’ sentencing hearing for Oct. 1. Defense lawyer Louis P. Aloise said after the hearing that his client would likely receive a light sentence because of his cooperation with the government’s ongoing investigation.