Silver Hawk, a prominent turf stallion who sired 66 stakes winners, has been pensioned at Brereton and Libby Jones' Airdrie Stud near Midway, Ky., where he entered stud in 1983 following a career in which he was a group II winner in England and runner-up in the Irish Sweeps Derby (Ire-I) and third in the Epsom Derby (Eng-I) for Buckram Oak Farm."He's been an extraordinary sire," Brereton Jones said about the 24-year-old son of Roberto. "Truly an international presence. We chose never to play the numbers game with this horse."Silver Hawk, who averaged about 40 foals a year, sired 34 graded or group winners, including champion and Epsom Derby winner Benny the Dip, Lady in Silver, Memories of Silver, Hawkster, Red Bishop, Silver Ending, Zoonaqua, Grass Wonder (in Japan), and Mubtaker, second in this year's Prix de l'Arc de Triomphe (Fr-I). Overall, about three-quarters of his $46 million in progeny earnings has come on turf.Bred by Clovelly Farms and produced from the Amerigo mare Gris Vitesse, Silver Hawk won three of eight races and $184,099.