RIO DE JANEIRO -(Dow Jones)- Brazilian state-run energy giant Petroleo Brasileiro (PBR, PETR4.BR), or Petrobras, is moving forward with its previously announced $13.6 billion divestment plan and should announce some sales in the second half of this year, Chief Financial Officer Almir Barbassa told Reuters in an interview published Monday. Petrobras is in the process of selling off non-core assets, most of them overseas, to raise cash needed to fund the company's massive $225 billion investment program, which is focused on developing recently discovered oil fields off the coast of Brazil. The discoveries, some of the world's largest finds in three decades, potentially hold billions of barrels of crude buried deep beneath the seabed. Petrobras has hired investment banks to negotiate the sales, which could include Petrobras's portfolio of exploration blocks in the U.S. Gulf of Mexico, Barbassa told Reuters. According to Reuters, Barbassa did not identify the banks or any potential buyers. "The assets in the Gulf of Mexico individually, perhaps, could be the most important," Barbassa told Reuters. Petrobras has also put refineries in Okinawa, Japan, and Pasadena, Texas, up for sale, and could sell off petrochemical, industrial and distribution assets as well, Barbassa told Reuters. Petrobras, however, is not interested in buying stakes in exploration blocks held by Brazilian mining company Vale SA (VALE, VALE3.BR, VALE5.BR), Barbassa told Reuters. Petrobras is a partner with Vale in some blocks, and contracts typically give partners first chance to buy stakes put up for sale. The ongoing European debt crisis and concerns about a global economic slowdown are not derailing Petrobras's investment plans, Barbassa added, but a steep drop in international oil prices could make pre-salt development inviable. The $225 billion program was based on oil at $80-to-$95 a barrel and the Petrobras has said that it can produce pre-salt oil for $45 a barrel. "Of course, if oil fell to $40 a barrel this plan is not viable," Barbassa told Reuters. Barbassa also said that the Brazilian real's recent weakness against the U.S. dollar is neutral for the company. A weaker local currency makes imports and the cost to service the company's dollar-denominated debts more expensive, but exports rise in value and royalty payments also decline, Barbassa told Reuters. -By Jeff Fick, Dow Jones Newswires; 55-21-2586-6085; Jeff.Fick@dowjones.com