Jimmy Lee, one of JPMorgan Chase & Co.'s most senior investment bankers, died on Wednesday, the U.S. bank's Chief Executive Officer Jamie Dimon said. Lee was 62.

Lee advised some of the world's biggest companies on deals, including the merger of United Airlines and Continental Airlines, the takeover of Wall Street Journal publisher Dow Jones by News Corp, and the initial public offering of Chinese e-commerce company Alibaba Group Holding Ltd.

"Jimmy was a master of his craft, but he was so much more - he was an incomparable force of nature," Dimon said in the statement.

Lee felt shortness of breath while running on a treadmill on Wednesday morning, according to a person briefed on the matter who requested not to be identified because of the sensitivity of the matter.