PETRORIO PUBLIC OFFER OF SHARES (FOLLOW-ON)

Petro Rio SA (“Company” or “PetroRio”) (B3: PRIO3), in compliance with the provisions of the Securities and Exchange Commission Instruction 358, of January 3, 2002, as amended, it informs its shareholders and the market in general that on this date its Board of Directors approved the beginning of the work and the procedures for choosing and contracting advisers with a view to conducting a public distribution offering with restricted efforts of nominative common shares , book-entry, without par value, free and clear of any liens or encumbrances, issued by the Company (“Offer” and “Shares”, respectively).

The offering will aim at raising an amount equivalent to approximately US $ 250,000,000.00 (two hundred and fifty million American dollars) by carrying out the Offer under the terms of the Securities and Exchange Commission Instruction 476, of January 16, 2009, as changed.

Once the Offer is settled, the net proceeds from the issuance of Shares will be used for investments in the Company’s assets and potential new business.

The Company will keep the market informed about the matter covered in this Material Fact.