Half-interest in the breeding rights to Preakness and Belmont Stakes winner Risen Star was sold for $7 million Friday, with the son of Secretariat scheduled to race only twice more and retire to stud at Walmac Farm.

Trainer-owner Louie Roussel III said the 3-year-old colt will retire from racing at the end of 1988. He said he plans only two more starts this year for the nation's leading money winner, with more than $2 million won.