Why did Citi's wealth management chief Todd Thomson abruptly decamp the firm “to pursue other interests” when he was often thought of as heir apparent to Citigroup’s Chuck Prince?

Yesterday, we reported that the management shake-up—a move that also restored Sally Krawcheck to head the wealth management unit (which includes Smith Barney, private client and investment research) —was all about cost control. (Krawcheck, a.k.a Mrs. Clean, was called in to clean up the Grubman mess in 2002; then, two years later, she was moved over to be CFO of Citi. Krawcheck, it is rumored, is being groomed for the top role at Citi.) For the full story, read "Krawcheck Back, Thompson Bows Out at Citigroup".

Apparently, the reason for Thomson’s leaving might have been something more than a desire to do his own thing. Bloomberg News reported, “Thomson, 45, was removed for a series of infractions that included inappropriate use of company aircraft, according to three people with knowledge of the decision.” (Read the full story here.)

The New York Post’s famous gossip column, Page Six, titillates by breathlessly reporting, “The financial giant Citigroup was strangely mum last night” on the reasons for Thomson’s departure, being that he was, the column says, “its 45-year-old fair-haired head of wealth management.” The column also reports that Thomson “got on the bad side” of Prince “by shuttling personal friends—including CNBC’s ‘Money Honey’ Maria Bartiromo—around the world on the company’s corporate jet.” (CNBC said Citi was paid for the flight.) Read the full story here.

For our story about Krawcheck’s first go-round as the wealth management chief of Citigroup, and her “march to $1 million” campaign (her goal to increase production of Smith Barney reps to $1 million), read "The New Smith Barney".