Brazil environmental regulator Ibama said on Dec. 7 it denied a permit to French oil major Total to drill in the environmentally sensitive Foz do Amazonas Basin for a fifth and final time.

Ibama said in a statement that it agreed with a technical assessment that indicated oil exploration in the area would present risks to reefs and biodiversity.

BP and Petrobras are also investors in the project near the mouth of the Amazon River, which is being operated by Total.

Ibama said it had given Total all possible opportunities to correct problems found during the technical evaluation and that the company had been informed of the decision earlier on Dec. 7.

Total has been seeking to explore the offshore basin, which geologists believe could contain up to 14 billion barrels of petroleum, or more than the entire proven reserves in the Gulf of Mexico, for more than four years.

The French company did not immediately respond to a request for comment.