Alan Marzelli, the longtime official who guided The Jockey Club through several decades of expansion into for-profit territories, will retire at the end of this year, the company announced on Friday.\nMarzelli will be succeeded by Jim Gagliano, who has been The Jockey Club's executive vice president and chief administrative officer since 2005.\nMarzelli, 55, has held top positions at The Jockey Club and at several of its affiliates for 23 years, and during that time, the organization expanded rapidly into for-profit business ventures, developed a host of software tools for breeding farms and racetracks, and led an effort to take control of the racing industry's past-performance data. The changes transformed The Jockey Club from a staid-but-stalwart breed registry into a multifaceted organization whose imprint reached from the offices of every major breeding farm to the myriad products that handicappers use to dope out races.\n"Alan has done a first-rate job for The Jockey Club with a wide range of initiatives, all of which have benefited this industry, and we're immensely grateful for his many contributions," Ogden Mills Phipps, the Jockey Club's chairman, said in a statement.\nMarzelli, who earned a degree in accounting from Fordham University, said on Friday that his retirement will allow him to pursue projects that he has neglected. He and his wife live in Ossining, N.Y., and own an apartment in Manhattan, where The Jockey Club has offices. \n"I have a lot of other interests that I want to pursue, be they charitable, civic, or social," Marzelli said. "Now is the right time to start doing that."\nMarzelli was hired as The Jockey Club's controller and assistant treasurer in 1983 after eight years at Deloitte and Touche, the accounting company. In 1986, he was promoted to chief financial officer and in 2003 to president and chief operating officer.\nThe Jockey Club's expansion was best illustrated by its role in the formation of Equibase, a for-profit data-collection company launched in 1990 in partnership with the Thoroughbred Racing Associations, a racetrack trade group. Equibase was The Jockey Club's first significant attempt to expand beyond its traditional role, and by 1998, with Marzelli in the lead, the company had supplanted its competition, the Daily Racing Form, to become the industry's sole commercial provider of past-performance information.\nMarzelli also led the effort to form InCompass, a technology company launched in 2001 by The Jockey Club to provide software and information technology products to racetracks and simulcast outlets. The company was an extension of The Jockey Club's ongoing efforts to create computerized tools for racing applications, including software for trainers, racing offices, and farms. \nMarzelli said on Friday that he would continue to serve as chairman of Equibase and represent The Jockey Club on the executive council of the International Federation of Horseracing Authorities through 2010. \nGagliano was executive vice president of Maryland racing operations for the Maryland Jockey Club and Magna Entertainment Corp. before joining The Jockey Club.