Citigroup executives in Mexico have bough millions of shares in the beleaguered U.S. bank as a show of confidence, a spokesman for the bank' Mexican unit told Reuters.

Robert Hernandez, chairman of Citigroup's subsidiary Banamex, bought 6 million shares of Citigroup. Manuel Medina-Mora, who leads Citi's Latin American business, bought 1.5 million shares, an SEC filing revealed.

They (the share purchases) are a show of confidence in the company’s future and its return to profitability, Banamex spokesman Paulo Carreno told Reuters in a statement.

In recent weeks, speculation has mounted that the New York based bank could sell the Banamex unit. Citigroup has denied it is interested in selling the unit.