The sudden departure this week of Todd Thomson, Citigroup’s head of global wealth management, centred on his use of the bank’s corporate jet to ferry Maria Bartiromo, America’s most influential television business presenter, from Beijing to New York, it emerged yesterday.

Mr Thomson’s failure to control his expenses, just as Citigroup was under pressure from investors to cut its rising costs, had put a growing strain in recent months on his relationship with Charles Prince, the bank’s chief executive.

Citigroup finally ousted Mr Thomson, 45, on Monday, saying that he was leaving to “pursue other opportunities”.

Mr Prince would add only that Mr Thomson was departing because his job was being taken by Sallie Krawcheck, Citigroup’s chief financial officer, in a move that many saw as a demotion, since it essentially returned her to her previous role in the bank.

However, Mr Thomson, nicknamed “Todd Mahal” by colleagues because of his sprawling office overlooking Central Park and his reputation as a free-spender, is thought to be leaving because his spending habits flew in the face of Citigroup’s stated mission to cut its costs.

The case that offended Citigroup the most is thought to centre on a trip to Beijing in November. It is understood that Mr Thomson flew a group of Citigroup employees to China, but left them there to make their own flight arrangements home, at considerable extra expense to the bank. Meanwhile, Mr Thomson flew back on the corporate jet, accompanied by Ms Bartiromo, anchor of the CNBC business channel and known as the “Money Honey”.

Adam Compton, an analyst for RCM Global Investors, said: “Citigroup investors have a big beef with the bank about its ability to keep expenses in line with revenues. This kind of thing sets a very bad example and you just can’t let that happen.”

Citigroup declined to comment on Mr Thomson’s use of its jet or to answer any question about his expenses. CNBC confirmed that Ms Bartiromo had taken the flight, but said that she had sought and received permission from the channel, which had paid the fare.

Last month Citigroup promoted Robert Druskin to the new position of chief operating officer, with a mandate to cut costs after mounting pressure from its shareholders, including Prince Alwaleed bin Talal, the Saudi billionaire.

Last week Citigroup reported a 26 per cent plunge in its fourth-quarter net income as a 23 per cent jump in its operating expenses outweighed a 15 per cent rise in its revenues.

Speculation as to who will replace Ms Krawcheck as Citigroup’s chief financial officer began yesterday, with Alvaro de Molina, Bank of America’s chief financial officer, tipped as a strong potential candidate.

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