Rosecroft Raceway, a harness track in Maryland, will be sold, possibly to Frank Stronach's Magna Entertainment. Magna has recently purchased a majority interest in the Maryland Jockey Club, which operates Pimlico and Laurel Thoroughbred tracks.The board of directors representing the owners of Rosecroft Raceway voted Sept. 18 to sell after listening to presentations by three potential buyers, including Magna Entertainment Corp., which made the highest offer.However, the board did not decide to whom to sell the track. It gave itself 30 days -- until Oct. 17 -- to decide among the three suitors or anyone else who steps forward with the highest bid, said Tom Chuckas Jr., Rosecroft's chief operating officer.He said the three bidders were Frank Stronach's Magna; Centaur Racing, part-owner of Hoosier Park in Indiana, and Greenwood Racing, the parent company of Philadelphia Park and its six off-track-betting sites in Pennsylvania.Chuckas said that the spokesmen for each company made offers that varied widely, but that this is how much each offer was worth: Centaur $47 million, Greenwood $49 million and Magna $68 million.Magna Entertainment Corp., which owns 10 tracks and has deals pending for four more, including Pimlico and Laurel, signed an agreement in July to buy 51% of the Maryland Jockey Club in a deal valued at $117 million.Jim McAlpine, Magna's president, made yesterday's presentation to the general membership of the Cloverleaf Standardbred Owners Association.The CSOA is the standardbred horsemen's group -- trainers, breeders and horse owners -- that owns Rosecroft Raceway. In a deal unusual in the horse industry, the association bought Rosecroft in 1995 to keep it from going bankrupt. The track has struggled in its attempt to compete with nearby harness tracks in Delaware.