Citigroup Inc named Michael Corbat permanent chief executive of Citi Holdings, a unit housing the Smith Barney brokerage and a variety of businesses and riskier assets that may be shed.

The move was the latest in a series of management changes under Chief Executive Vikram Pandit, who is trying to nurse the the third-largest U.S. bank back to health after $37.5 billion of losses over 15 months.

Among other changes, announced Monday in several internal memos, Eric Aboaf was appointed treasurer and Paul Galant was named to run North America credit cards and international cards. Citigroup confirmed the memos' contents.

Corbat, 48, had been interim chief of Citi Holdings since January 16, when Citigroup split its operations in two, creating Citicorp and Citi Holdings. He has worked at the New York-based bank for more than 25 years, most recently as chief executive of global wealth management.

Gary Crittenden, who had been Citigroup's chief financial officer, was named chairman of Citi Holdings last month.

Citi Holdings has about $850 billion of assets, including Smith Barney, which is merging into a joint venture with Morgan Stanley's brokerage; the CitiFinancial and CitiMortgage finance operations; the Primerica insurance unit; and the Nikko Cordial unit in Japan.

It also houses $300.8 billion of troubled assets. In November the U.S. government agreed to share in losses from those assets. Citigroup has received $45 billion of taxpayer money under the government's Troubled Asset Relief Program.

Citicorp has about $1.1 trillion of assets and businesses the bank wants to keep, including retail and investment banking, transaction services and Citi Private Bank.

Aboaf, 44, joined the bank in 2003 and was most recently chief financial officer of Citigroup's institutional clients group, a position that for now is vacant. He reports to Edward Ned Kelly, who succeeded Crittenden as Citigroup CFO.

Zion Shohet, who had been treasurer, was named chief operating officer of the institutional clients group. He succeeds Hamid Biglari, 50, who becomes vice chairman of Citicorp.

George Awad, who had been chief executive of North America cards, is joining Citi Holdings' senior leadership. Mark Mason was named COO of Citi Holdings, and Vince Nerlino succeeded Mason as CFO and head of strategy for Citi Holdings.

Francesco Vanni D'Archirafi succeeds Galant as head of global transaction services and was replaced by Paul Simpson as head of Treasury and trade solutions.

Citigroup was unavailable for further comment. The bank's shares fell 12 cents to $2.73 in afternoon trading on the New York Stock Exchange.

(Reporting by Jonathan Stempel and Dan Wilchins; Editing by Gerald E. McCormick and John Wallace)