RIO DE JANEIRO, Feb 13 (Reuters) - Brazilian state-run oil company Petrobras PETR4.SA hopes to settle details of a tie-up with Mubalada to take back control of the operation of a refinery owned by the Abu Dhabi sovereign investor by the end of the first half of the year, Petrobras' chief executive said on Tuesday.

CEO Jean Paul Prates said on X, formerly Twitter, that both firms will intensify efforts on the corporate and operational details of the deal over the Landulpho Alves Mataripe Refinery (RLAM), in Brazil's northeastern state of Bahia.

The refinery was sold under previous management to Mubalada in 2021 for $1.65 billion, as part of a divestment strategy enacted during the far-right administration of former President Jair Bolsonaro.

Last year, after leftist Luiz Inacio Lula da Silva took office, Petrobras suggested it could buy back refining assets to boost its fuel production.

Prates gave no further details on how the deal would work, but Petrobras has previously said in a securities filing that it would "evaluate the acquisition of a stake" in RLAM and Mubadala-owned Acelen Renewable Energy.

RLAM accounts for about 10% of Brazil's oil refining capacity.

Petrobras did not immediately reply to a request for comment on a public holiday.

Prates also said the partnership would include boosting Mubadala's biofuel business in Brazil, gave no further details.

In September, Petrobras signed a memorandum of understanding to study joining Mubadala in its downstream operations in Bahia, including a biorefinery in which the Abu Dhabi fund estimates $2.5 billion of investment would be needed.

At the time, sources told Reuters that the partnership could open the door to talks on RLAM as Petrobras remained keen to repurchase the refinery, despite potential antitrust hurdles.

(Reporting by Fabio Teixeira; editing by David Evans)

((Fabio.Teixeira@thomsonreuters.com; +55 21 99603-4782;))