Potential buyers reportedly include: Indalo Group owner Cristobal Lopez, whose holdings include a television news channel, cattle ranches and casinos; and Eduardo Eunerkian, owner of Corporacao America, which operates airports in Buenos Aires and Montevideo, and recently won a tender to operate an airport terminal in Brazil's capital, Brasilia.
Both Lopez and Eunerkian are considered allies to controversial Argentine President Cristina Kirchner.
Petrobras has been dissatisfied with its relationship with Argentina for years, according to Brazilian newspaper Folha de Sao Paulo.
Petrobras last year sold a refinery in Argentina. Petrobras Argentina, which controls units in Bolivia, Venezuela, and other South American countries, reported earnings of BRL505.3 million (US$256 million), a 16 percent decline from 2011 earnings.