James B. Lee | Financier, 62

James B. Lee, 62, the colorful JPMorgan Chase & Co. rainmaker whose pioneering work in the loan market helped propel an era of Wall Street deals, died Wednesday. He felt shortness of breath while exercising at his home in Darien, Conn., and was taken to a hospital, where he died, according to a person briefed on the matter.

"Jimmy was a great friend, leader and mentor to me and so many others," JPMorgan chief executive officer Jamie Dimon said in a statement. "Jimmy was a master of his craft, but he was so much more - he was an incomparable force of nature."

At an investment bank that often emphasized its team and resources over individual stars, Mr. Lee was the exception, with a charismatic personality and Rolodex known throughout Wall Street. He had worked for New York-based Morgan and its predecessors since about 1975, eventually running its investment bank before becoming a company vice chairman and continuing to garner some of its biggest deals.

Having built a career making loans and selling bonds, Mr. Lee was a primary architect of the modern private-equity industry, pioneering the use of leveraged loans to fund takeovers starting more than two decades ago.

"Jimmy was a great banker, a tireless mentor, and not the least, everyone's favorite golfing partner," said Michael Bloomberg, founder, CEO, and majority owner of Bloomberg LP, parent of Bloomberg News. "He will be sorely missed and our thoughts and prayers go out to his wife Beth and their daughter and two sons." - Bloomberg