Oil producer Chevron is in talks with the U.S. government to expand a key license to operate in Venezuela so it can increase crude exports to its own refineries and sell to other buyers, four sources close to the negotiations said on Wednesday.

Warren Buffett's Berkshire Hathaway owns about 6% of Chevron, the only US oil major still operating in Venezuela.

Chevron Corporation (NYSE:CVX) manufactures and sells a range of high-quality refined products, including gasoline, diesel, marine and aviation fuels, premium base oil, finished lubricants, and fuel

President Donald Trump has called for billions of dollars in investment in the country following the capture of Nicolas Maduro.

Chevron ( CVX 0.79%) is lining up with private equity group Quantum Energy in a bid for sanctioned Russian oil company Lukoil's international assets, the Financial Times reports. Lukoil said last year it would sell its non-Russian operations.

A former Chevron executive is seeking $2 billion in investment for oil opportunities in Venezuela as the U.S. shows interest in rebuilding the country's petroleum industry following the capture of its former leader.

US oil giant Chevron and private equity firm Quantum Capital Group have partnered on a bid for sanctioned Russian oil company Lukoil's international assets, valued at $22 billion, the Financial Times reported Wednesday.