<p>John Selvaggio, president of Song, Delta Air Lines Inc.'s leisure market unit, announced his retirement Friday, effective immediately.</p><p>Selvaggio led the creation of Delta's latest airline-within-an-airline experiment in April, 2003, when it was a pet project of former chief executive Leo Mullin. And he helped fight to keep Song alive after Gerald Grinstein, took over as CEO in January, and made it clear he thought it was a bad idea.</p><p>Atlanta-based Delta is the third-largest U.S. airline and is struggling to pull out of a three-year financial tailspin.</p><p>Selvaggio is the latest in a series of departures by executives at the beleaguered airline. Last week Vicki Escarra, executive vice president and chief customer service officer, announced her retirement. Mullin announced his retirement last fall, and was followed this spring by Frederick Reid, former chief operating officer, who left to become head of Virgin Group's effort to launch a new low-fare U.S. airline.</p><p>Former chief financial officer, Michelle Burns, also resigned this spring, taking the same position at energy concern Mirant Corp. Several other middle- and upper-level executives have also departed.</p><p>Song is Delta's answer to low-cost carrier JetBlue Airways Corp., going toe-to-toe on leisure routes, particularly between Florida and the Northeast. The lime-green paint scheme, simplified fares, one-class service, leather seats and in-flight entertainment units at every seat, all are intended to compete with JetBlue's cheap chic image.</p><p>Paul Matsen, Delta's chief marketing officer, said in a memo that Selvaggio was leaving "to pursue personal interests."</p><p>"I leave here knowing Song is well-positioned and fully supported as a strategic and vital part of Delta's transformation and future," Selvaggio said in a memorandum to employees on Friday.</p><p>Joanne Smith, Song's vice president of marketing, will lead the unit until a permanent replacement is named.</p>
