Citigroup Inc (C.N) chairman Michael O'Neill bought $1 million of the bank's stock about a month after the exit of chief executive Vikram Pandit.
O'Neill acquired 28,200 shares through a trust at an average price of $35.52 each, the third-biggest U.S. bank said on Wednesday in a regulatory filing.
O'Neill hand-picked new CEO Michael Corbat after the departure of Pandit in mid-October.
Shares of Citigroup closed at $35.07 on Wednesday on the New York Stock Exchange.
(Reporting by Ritika Rai in Bangalore; Editing by Richard Pullin)