BOSTON (AP) — Jack Welch, who transformed General Electric Co. into a highly profitable multinational conglomerate and parlayed his legendary business acumen into a retirement career as a corporate leadership guru, has died. He was 84. His death was confirmed Monday by GE. The cause of death was renal failure, his wife Suzy told The New York Times. Welch became one of the nation's most well-known and highly regarded corporate leaders during his two decades as GE's chairman and chief executive, from 1981 to 2001.