The chief executive of Brazil's Oleo e Gas Participacoes said Thursday he is confident the oil and gas company will manage to exit bankruptcy protection despite efforts by some of its creditors to derail the company's restructuring plan.

Bondholders will gather in Rio de Janeiro to vote Tuesday on a restructuring plan for the company, formerly known as OGX. Earlier this week, one of the company's creditors was able to get an injunction from a judge in Rio aimed at stopping that vote.

The order allows only the trustee--Deutsche Bank AG--to vote rather than all the company's bondholders, which hold some $3.6 billion in debt.

Oleo e Gas is trying to reverse the injunction obtained by the creditor, said Darwin Correa, a lawyer at Paulo Cezar Pinheiro Carneiro law firm, which represents the oil company. People close to the former OGX say it wouldn't be surprised if other injunctions were produced before Tuesday.

Smaller bondholders have said they weren't treated fairly during the company's restructuring-plan talks and weren't given the same chance to invest in the company's funding plans as its large bondholders.

Speaking at company headquarters on Thursday, CEO Paulo Narcelio said investors who initially didn't want to risk investing in OGX are now being opportunistic.

"No one wanted to lend us money in the beginning," he said.

Oleo e Gas, formerly known as OGX Petroleo e Gas Participacoes SA, helped Brazilian businessman Eike Batista become the country's richest person, before it failed last year.

Oleo e Gas doesn't expect the recovery plan to be rejected. If it were, it would lead to the company's liquidation. However, the injunction could delay a decision on the restructuring plan.

"The firm's liquidation would be the worst scenario for all," Mr. Narcelio said.

OGX was founded in 2007 and sold to investors as a promising global oil firm. After failing to meet production targets, it filed for bankruptcy protection in October in the largest corporate collapse in Latin America.

At the end of last year, some of its main creditors, including Newport Beach, Calif.-based Pacific Investment Management Co., agreed to invest $215 million in the company to try to make it viable.

If the restructuring plan is approved, those creditors will control Oleo e Gas. In that event, Mr. Batista's stake would be cut to about 5%. Some creditors have claimed that large investors were offered better terms to invest than some smaller ones.

"We can't change what has been agreed with the ones who believed in the company during its worst times," Mr. Narcelio said.

He said if the restructuring is approved, the firm's main challenge will be to finance its investment plan for 2015. The company will need some $500 million to continue developing its oil fields, including the Tubarao Martelo offshore field and Hammerhead Shark, off Rio de Janeiro. Mr. Narcelio said one funding option might be the partial assignment of the company's oil blocks, were the restructuring plan approved.

Even after a collapse, Oleo e Gas may try to go back to the capital markets to fund itself, Mr. Narcelio said.

"We want to attract large investment firms to cover our stock again," he said, while acknowledging that the company will need to overcome the stigma of the collapse.

At one time, the company planned for production of 1.4 million barrels of oil a day by 2019. Mr. Narcelio's current estimate is for production of 60,000 barrels a day by 2020.