Exhibit 99.1

Itaú Unibanco Holding S.A.

CNPJ. 60.872.504/0001-23   A Publicly Listed Company NIRE 35300010230  

Announcement to the Market

Trading of Own Shares for Treasury

 Month: April 2017

1. We announce to the capital market agents that, during April 2017^(a), Itaú Unibanco acquired 7,461,800 preferred shares, and the average acquisition price^(b) was R$ 38.08, totalizing approximately R$ 284.2 million.

1. In this program^(a), between November 2016 and April 2017 we acquired 38,087,800 preferred shares at the average acquisition price^(b) of R$ 34.54.

3. Historical information is available on the organization's Investor Relations website (www.itau.com.br/investor-relations).

São Paulo-SP, May 3, 2017.

MARCELO KOPEL

 Investor Relations Officer

(a) According to the Material Fact published on 02/02/2016, these acquisitions relate to the buyback program approved by the Board of Directors that renewed the limit for purchases of up to 10.0 million common shares and 50.0 million preferred of own shares for the period from 02/03/2016 to 08/02/2017.

(b) The repurchase amounts do not include settlement, brokerage and trading fees.