A Hennessy colt produced from the unraced Alydar mare Altair was purchased for $1.1 million on behalf of Coolmore Stud interests to top Thursday's session of the Keeneland September yearling sale.The colt, consigned by FitzGerald/ Keogh, descends from a female family that includes Kentucky Derby winner Cannonade, champion Tosmah, and leading sire Halo, and other top stakes horses.Aisling Cross, of Coolmore-owned Ashford Stud, signed the sales receipt on behalf of Irish agent Demi O'Byrne. "He is an absolutely beautiful horse," Cross said. "We were lucky to get him."Also pursuing the colt were Robert McMartin, representing Eugene Melnyk, and J. B. McKathan.Mr. and Mrs. Jerry S. Moss had paid the session's second-highest price of $375,000 when they bought a Tale of the Cat--Thorough Fair (by Quiet American) colt from Bruce Kline's Spendthrift Farm consignment.John Ferguson, who represents the Maktoum family, had paid the third-highest price of the session, going to $300,000 for a Theatrical--Rihan (by Dayjur) colt from the consignment of K. T. Roden's Warrendale Sales.Following a one-day break Friday, the sale in Lexington, Ky. resumes Saturday and continues through Sept. 22.