Petroleo Brasileiro (Petrobras) will need an additional investment of $4.3bn for completing development of Comperj refinery project which is located at Itaboraí, outside the city of Rio de Janeiro in Brazil.
The project, which is stalled at present, has already cost the company around $11bn.
Over 80% works for the project have been completed.
The firm intends to complete the first unit or 'train' at the facility by 2020, which is expected to have a production capacity of 165,000 barrel-a-day. According to the company website, it was intended to be operational in August 2016.
Petrobras refining chief Jorge Celestino Ramos was cited by Reuters as saying that the firm is presently seeking a partner, in a bid to complete the project sooner.
Comperj refinery can turn out to be one of the most expensive oil refineries in the country, with an estimated cost of about $93,000 for each additional barrel of refining capacity.
The firm had stopped working on the project in late 2014 due to a corruption scandal at the time which had raised concerns about overspending and bribery for refining projects.
Many of the contractors involved in the project had declared bankruptcy at the time.
The scandal and the decreasing oil prices had prompted Petrobras to attempt reduction of its existing debts of $132bn.