A first round of indictments involving allegations of criminal activity at betting window operations at New York Racing Association tracks is expected today, sources said Wednesday.In a double-dose of bad news for NYRA, other officials said New York City Mayor Rudolph Giuliani has tentatively scheduled a news conference for Thursday morning to announce the winning bidder for New York City Off Track Betting Corp. A group led by Magna Entertainment, not NYRA, is in line to win the lucrative contract, the officials said.A task force of New York state agencies, led by Attorney General Eliot Spitzer's office, is scheduled to make an announcement Thursday regarding allegations of criminal activities at the NYRA tracks. Officials would not comment on the nature of the announcement.It was unclear Wednesday how far up NYRA's chain of command the indictments will go, but sources in recent weeks have said they expect the initial announcement to focus mainly on lower-rung personnel. "It represents the beginning, not the end, of possible criminal cases," one state source said Wednesday.News of the probe likely heading to the court phase comes as sources told the Blood-Horse that Giuliani has finally made up his mind on the NYCOTB sale after months of delays. An 11 a.m. news conference Thursday was being planned by the Giuliani administration to unveil the winner of a much-delayed bidding war between NYRA and a team headed by Magna Entertainment for ownership rights to NYCOTB.Officials close to the talks who requested anonymity said the Magna team has been tapped by Giuliani to buy the OTB. They said Magna had offered at least $100 million more than NYRA for the OTB, which last year handled more than $1 billion in bets. Giuliani recently told legislative leaders he was "leaning" toward Magna because they offered a far better financial deal for the city.NYRA racetracks were raided last fall by state and federal agents who examined patterns of widespread abuse that were initially identified in the mutuel department. Various alleged violations of laws involving tax evasion and money laundering were among the areas investigators examined. Officials at the time said there was evidence mob elements were involved in some schemes at the tracks. Investigators suspected "dirty" money obtained from drug deals and robberies was being "cleaned" at the track with the help of tellers and possibly other NYRA officials.NYRA executives in the past have said they were working closely with investigators on the criminal probe.The attorney general's Organized Crime Task Force and federal agents raided NYRA's three tracks last September. Dozens of clerks were later called into to testify in the investigation.The looming sale of NYCOTB to Magna would send shockwaves through New York's racing industry, which has long been dominated by NYRA. Magna and NYRA have feuded openly and increasingly aggressively over the NYCOTB purchase deal.If Magna is tapped by Giuliani, NYRA officials plan an all-out lobbying assault to stop the sale at the state Capitol, where approval is needed because the sale would require a host of changes in state law. In addition, a city employees union representing OTB workers has already sued in court to block the sale.But Magna has its own formidable lobbying force, led by a former state GOP chairman and a top aide to Democratic Assembly Speaker Sheldon Silver.