(Adds share price)
SAO PAULO, Aug 27 (Reuters) - The board of Itaú Unibanco Holding SA, Brazil's largest lender by market value, has approved the buy-back of up to 11 million common shares and 55 million preferred shares, the bank said on Thursday in a securities filing.
The program involves less than 10 percent of the 287,786,288 common shares and 2,921,796,086 preferred shares on the market, the bank said.
Preferred shares of Itau Unibanco closed at 28.34 reais on Thursday, up 3.54 percent, while ordinary shares ended 2.66 percent higher at 26.65 reais.
The bank announced at the end of July that it would buy back 11 million ordinary shares and 55 million preferred shares, but the offer was shut down earlier than planned.
Itau Unibanco reported a second-quarter profit of 6.134 billion reais before one-time items, a quarterly record, though a bigger-than-expected jump in loan defaults cast a shadow over the strong result.
Reporting by Alberto Alerigi Jr.; Editing by Dan Grebler and Leslie Adler