Petrobras America Inc., a Houston-based subsidiary of Petroleo Brasileiro SA, Rio de Janeiro, Brazil, (NYSE: PBR) has acquired the 20% working interest in the Cottonwood project in the Gulf of Mexico from Mariner Energy Inc., Houston, (NYSE: ME) for US$31.8 million. The project is approximately 240 miles southwest of New Orleans and includes Garden Banks Block 244, which features two subsea wells. Petrobras America is operator.