RIO DE JANEIRO, Dec 28 (Reuters) - Private equity firm EIG Partners has reached a deal to acquire Brazilian oil industry supplier Ocyan in a deal valued at $390 million, EIG said on Thursday.

EIG will pay $283 million of that sum to Ocyan's owner - the conglomerate Novonor, formerly known as Odebrecht - and the remainder to settle the outstanding balance of its bonds.

Ocyan, which provides services to oil and gas companies, operates four floating production, storage and offloading (FPSO) units through a joint venture with Altera Infrastructure and owns two of them.

"Between 70% and 80% of the value of what we are buying comes from the FPSOs," Flavio Valle, EIG managing director for Brazil, said in an interview.

The company is also eying future tenders from state-run oil firm Petrobras and other oil companies operating in Brazil.

"We want to go from (owning) two FPSOs to four ... we want to play in the middle size, with platforms with a capacity of 80,000 to 100,000 barrels per day," Valle said.

Ocyan also has long-term operating contracts with Libra Consortium, Karoon Energy and 3R Petroleum.

The sale should be concluded in the first quarter of 2024. (Reporting by Rodrigo Viga Gaier in Rio de Janeiro Writing by Peter Frontini Editing by Matthew Lewis)