CHEVRON CORPORATION 
Rosneft (>> NK Rosneft' PAO), Russia's top oil producer, has been offered a 10 percent stake in the Petropiar joint venture.
PDVSA, as Petróleos de Venezuela SA is known, has a 70 percent share, and U.S. oil company Chevron Corp (>> Chevron Corporation) holds 30 percent of the venture, which includes an oil field and a 210,000 barrel-per-day oil upgrader.
Two sources said the offer was part of a larger package offered to Rosneft as PDVSA seeks to raise money to pay suppliers and bond holders.
It is unclear if Rosneft will accept the offer. Financial details of the potential transaction were not immediately available.
PDVSA and Venezuela's Oil Ministry did not respond to requests for comments. Chevron and Rosneft declined to comment.
A deal would see California-based Chevron working alongside state-owned Rosneft, which has been affected by U.S. sanctions against Russia.
But Chevron's main concern is that accounting and transparency laws are less strict in Russia than in the United States, a source close to the matter said.
The proposal highlights Venezuela's need for cash after the nation's oil output fell about 10 percent last year, according to the Organisation of the Petroleum Exporting Countries. This has worsened a recession that has millions of Venezuelans skipping meals amid food shortages and spiraling inflation.
The opposition-controlled National Assembly says President Nicolas Maduro's unpopular government is resorting to surreptitiously selling strategic assets to weather the unprecedented crisis.
"Any deal of national interest must be approved by the National Assembly," tweeted lawmaker Jose Guerra, head of congress' finance commission, in reaction to Reuters' article. "If PDVSA sells 10 (percent) of Petropiar to Rosneft, that sale is null and void."
MOSCOW'S MUSCLE
Rosneft has already been gaining ground in Venezuela, an OPEC member.
Last year, the company paid $500 million to increase its stake in the Petromonagas joint venture from 16.7 percent to 40 percent, the maximum foreign partners are allowed to have under oil sector regulations created under late leader Hugo Chavez.
"The ballpark value of the two projects (Petromonagas and Petropiar) probably isn't that different," said Francisco Monaldi, fellow in Latin American energy policy at the Baker Institute in Houston.
The Petromonagas sale also raised the ire of the National Assembly, which said the purchase was illegal because Congress did not approve it. Critics have also said the stake was sold too cheaply.
In another controversial move, PDVSA last year used 49.9 percent of its shares in coveted U.S. subsidiary Citgo as collateral for loan financing from Rosneft.
PDVSA said this month it had received $1.985 billion from an unnamed client in return for future oil shipments, with Citgo shares used as a guarantee.
In total, Rosneft has lent PDVSA between $4 billion and $5 billion, but the details of those deals have not been disclosed.
"We must thank life that Russia and the world have a Vladimir Putin," Maduro said at a deal-signing event with Rosneft head Igor Sechin last year.
"I wanted to be here at this event because of how important relations with the new Russia are."
(Additional reporting by Ekaterina Golubkova and Vladimir Soldatkin in Moscow; Writing by Alexandra Ulmer; Editing by Cynthia Osterman)
By Alexandra Ulmer and Marianna Parraga
