Karoon Gas Australia’s US$1.5 billion purchase of the offshore Bauna and Tartaruga oil projects in Brazil from state-run oil company Petrobras remains in doubt.

Karoon revealed Tuesday the Federal Court of Sergipe had rejected Petrobras’ appeal to lift an injunction suspending the sale, which was granted in November.

The court case stems back to proceedings initiated in October claiming Petrobras had not complied with the relevant regulatory requirements during the sale of the offshore fields which required an open and public bidding process be carried out.

Petrobras