Miller, who had been chief financial officer of Travelers and Citigroup before a short but painful stint at Priceline.com, is now Dimon's CFO, two months after joining Bank One.
Why the executive musical chairs? Dimon says Miller's sudden job switch was sparked by his wish to give CFO Charlie Scharf some line responsibility. Dimon, who has known Scharf since they both worked at Sandy Weill's Commercial Credit Corp. in the 1980s, says Scharf did not join Bank One two years ago "to be CFO forever." With Miller taking his job, Scharf is freed up to run Bank One's retail operation. Says Dimon of his shifting of the executive ranks: "It's important to have your top people know all the businesses. We're starting to develop a management depth and bench so we can do things like this."