Representatives of the nation’s thoroughbred trainers and...

Representatives of the nation’s thoroughbred trainers and the Del Mar Race Track offered to cooperate with immigration officials to head off raids that could end the Del Mar racing season.

The Horsemen’s Benevolent & Protective Assn. delivered a letter to the Immigration and Naturalization Service in which the group pledged to make every effort to fire illegal aliens working as grooms and hot-walkers and to hire American citizens and legal resident aliens to fill the vacancies.

Robert Frankel, president of the state chapter of the Horsemen’s Assn., said that the loss of skilled handlers could force he and his fellow trainers to drop out of the Del Mar meet, which runs through Sept. 11.

The Border Patrol estimates that as many as 1,500 illegal aliens work at the Del Mar track.