Petrobras to reluctantly mull big Carabobo stake

RIO DE JANEIRO, March 31 (Reuters) - Brazil's state oil company Petrobras will consider taking a bigger stake in Venezuela's heavy oil Carabobo project than the share of up to 10 percent it has been studying, a top company official said on Monday.

The statement comes after last week's meeting between Brazilian and Venezuelan leaders, where Brazilian President Luiz Inacio Lula da Silva appeared to insist on a larger participation by Petrobras (PETR4.SA)(PBR.N) of 40 percent -- the way the project had been devised from the start.

Petrobras' downstream director Paulo Roberto Costa told reporters studies on the costly project would continue for two months, and if Petrobras gets assurances of adequate return it may take a bigger stake.

"Up to last week we were studying a stake of no more than 10 percent," he said, declining to comment on whether there has been pressure on Petrobras from the government.

"In the next 60 days we may have changes in the setting which could allow a bigger participation ... if we have more clarity on investment, returns and time terms," said Costa, who did not rule out taking no stake in Carabobo at all.

"The costs are high because the oil lies deep and it is heavy. Investment would be big, including in exploration and production, many wells, many pipelines and an upgrader," he added. "We'll decide whether we take 10 percent, more than 10 percent or if we are not going to take part."

As a publicly traded company, Petrobras is less at the whim of the government than Venezuela's PDVSA and it has a giant light oil project to develop at home in the next few years.

If it refuses the 40 percent Carabobo stake, PDVSA would hold a tender for the outstanding participation, Costa said.

Lula and his Venezuelan counterpart Hugo Chavez pledged on Thursday to speed up energy integration between the two countries and advance talks on building a joint gas pipeline from Venezuela to Brazil and Argentina, as well as producing and refining oil together.

The Carabobo project is linked to a plan to build a $4 billion oil refinery in Brazil's northeast. Last Wednesday, Lula and Chavez agreed in principle that PDVSA would take a 40 percent stake there and Petrobras the remaining interest.

Contrary to statements by Venezuelan officials, Costa pointed out the final contract was yet to be signed.

"It's a preliminary stakeholders agreement. It's not a definitive deal yet. We still diverge on some clauses. But I believe it is possible to sign the contract as differences are minor," Costa said. (Reporting by Rodrigo Gaier, writing by Andrei Khalip)