And Lee's hard work has enabled him to keep ringing the cash register for JPMorgan even in a relatively quiet time for deals. For example, he helped lead a deal where JPMorgan helped finance DirecTV Group ( DTV) parent Liberty Media's $530 million investment in Sirius XM Radio ( SIRI) to keep it out of bankruptcy court. He is also part of a JPMorgan effort to win the financing mandate for General Motors' emergence from bankruptcy. And if the equity markets stay healthy, private equity clients will undoubtedly look to him to help take their portfolio companies public. Lee's fans are not restricted to the private equity realm, however. News Corp.'s Murdoch says he consults regularly with Lee, and gives him a great deal of credit for helping him buy Dow Jones in 2007 -- a deal many believed was impossible, because the Bancroft family that had owned the company for 105 years was thought to be totally opposed to the idea. "He knew it was something I'd given a thought but he actually made the contacts and got things together," Murdoch told TheStreet.com. "Without him it wouldn't have happened or would have happened much later." JPMorgan watchers say it is hard to imagine Lee, whose office is next to Dimon's, going anywhere else. One year, after Lee organized the firm's annual CEO schmoozing event in Deer Valley, Utah, he received a thank you note from Dimon's wife and hung it on a wall in his office. Not that Lee hasn't had his chances to go elsewhere. Schwartzman, Blackstone's chairman and CEO, almost hired him away six years ago. "That was a missed opportunity, but it worked out fine for him," Schwarzman told TheStreet.com. "We were quite close at that time to a deal. But he's been extremely loyal to JPMorgan over the years." Lee's popularity among private equity clients is no doubt linked to his role as a gatekeeper. "The most important thing about Jimmy is he can deliver," says Glenn Hutchins, co-founder of Silver Lake, a $16 billion private equity giant. "At JPMorgan they run a very transparent process. You know when they're going to make the commitment and when they do commit, Jimmy stands by the commitment. So you can do business with him in a very efficient, predictable and reliable way."