Itaú Unibanco Holding SA on Dec. 15 approved a new share buyback program for the repurchase of 28,616,649 common shares and 50,000,000 preferred shares.

The new program takes effect Dec. 20, according to a Form 6-K filing.

The financial amount spent for the buyback will not have significant accounting effects on the company's results, Itaú noted.

Itaú also canceled 31,793,105 common shares it reacquired in an auction earlier in December, through a buyback program approved in August.