A contract dispute over simulcasting revenue between the Thoroughbred Owners of California and tracks owned by Churchill Downs led the owners' group to withdraw permission to send the Santa Anita betting signal on Monday to at least two major Churchill-owned venues, officials of Santa Anita and the owners' group said.\nThe simulcasting networks at Arlington Park, near Chicago, and Fair Grounds in New Orleans were cut off, as were satellites linked with those racetracks. The extent of the blackout to other Churchill-owned tracks or simulcasting networks was not immediately known.\nThe blackout took effect on Monday, a day in which Santa Anita ran a nine-race program.\nDrew Couto, president of Thoroughbred Owners of California, said the dispute centers around the distribution of revenue among racetracks, simulcasting locations, and horsemen from bets placed through Churchill Downs-owned venues.\nCouto said he was informed last Thursday that Tracknet, a simulcast-marketing partnership between Magna Entertainment Corp. and Churchill Downs Inc., wanted to alter the rates it pays to offer simulcasting. A contract agreement was reached with the Magna-owned tracks in the Tracknet group, but no resolution was reached with the Churchill-owned tracks, he said.\nThe blackout began Monday after negotiations reached a stalemate last week, Couto said.\n"We gave them a 72-hour notice on Friday," he said.\nTracknet's chief executive, Scott Daruty, said, "I fail to see how that could and should result in the cutting off of the signal to other racetracks. I think this whole thing is thoroughly avoidable. I think the signals could have been left on while we try to find common ground."