The CEO of Brazil's Petrobras said the state-controlled company is searching for downstream partners and lamented delays in formalizing the participation of Venezuela's PDVSA in a refinery joint venture.

"There's interest from possible partners, but the names are absolutely confidential," Maria das Gracas Foster told reporters after a public hearing in Brazil's lower house.

According to Foster, Brazil is currently evaluating "the profile of interested parties" with a view to launching possible negotiations in the near future.

She said the so-called "pre-salt" region, a recently discovered, ultra-deep hydrocarbon frontier off the coast of Rio de Janeiro state, "has greater potential than expected" and should enable the country to boost its current refining capacity.

The pre-salt fields - distributed across roughly 160,000 sq. kilometers (62,000 sq. miles) - are estimated to hold tens of billions of barrels of crude and could potentially transform Brazil into a major crude exporter.

But accessing the fields will be very costly and pose an enormous technical challenge because they are located at depths of up to 7,000 meters (22,950 feet) under a shifting layer of salt.

"If we find good partners in (the refining) area, we'll sit down and talk," Foster said, adding that Venezuela's PDVSA remains "a potential partner we're negotiating with."

The CEO said it would be a "very significant" development if the Venezuelan company were to formalize its participation in the bi-national Abreu e Lima refinery in the northeastern Brazilian state of Pernambuco because "it's a company with a great deal of experience in the (refining) area."

"It's regrettable they're not with us yet," Foster said.

The two companies agreed to jointly build the 230,000 barrel-per-day refinery seven years ago.

But Petrobras began constructing the plant in 2007 without any contribution from PDVSA, which has not yet met its component of the financing arrangement with Brazil's BNDES state development bank.

To formally enter the joint venture, PDVSA must acquire a 40 percent stake in the refinery and assume responsibility for an equal percentage of the loan and its share of what Petrobras has already spent in the construction phase.

PDVSA and Venezuelan President Hugo Chavez have repeatedly reaffirmed their interest in Abreu e Lima, but the company has not yet provided BNDES sufficient guarantees for its share of the loan.

Petrobras has given PDVSA until November to decide if it will participate in the project.

The U.S. Energy Information Administration noted in a country analysis brief this year that Petrobras plans to boost its Brazilian refining capacity to more than 3.1 million barrels per day by 2020 - up from less than 2 million bpd at present - to meet "burgeoning domestic demand."

Abreu e Lima is a key component of this objective because it will be "designed to process heavy Venezuelan and Brazilian crude oil."

Brazil's refining capacity is still relatively simple, "meaning that the country must export some of its heavy crude oil production and import light crude oil," the EIA said, adding that "with domestic demand growing, Brazil's refineries are currently operating at full capacity." EFE