The Thoroughbred Racing Associations and Harness Tracks of America, two trade associations already linked through the Thoroughbred Racing Protective Bureau, are pursuing a "structured relationship" that would allow them to share information and work on joint projects.The relationship -- not a merger, officials said -- has been discussed at recent TRA and HTA conventions."We've done a lot of work toward that," TRA executive director Chris Scherf said. "The two organizations would remain independent. We're seeking to identify things we can do together. Racetrack owners can learn from each other."The TRA's security arm, the TRPB, has a subsidiary called Standardbred Investigative Services, which serves the HTA and the United States Trotting Association. The TRA and HTA also join forces each year to host a simulcasting conference."It's a work in progress as far as I'm concerned, but I think we're drawing closer to a cooperative effort," HTA executive vice president Stan Bergstein said. "I've always been a believer in ecumenicalism (in the pari-mutuel industry)."The TRA, based in Fair Hill, Md., has about 50 member racing associations, and the HTA, based in Tucson, Ariz., about 35 members. Tracks such as Meadowlands and Woodbine, which offer dual-breed racing, are members of both organizations.