Russian oil giant Lukoil is discussing a joint venture with ConocoPhillips of the US, according to a press report.
Lukoil chief Vagit Alekperov and James Mulva of ConocoPhillips opened talks on a joint venture in September, the Financial Times reported.
"This process is under way," the FT quoted Lukoil vice president Leonid Fedun as saying.
The joint venture would focus on oil fields in northern Russia with a reserves of a billion barrels of oil.
But Mr Fedun stressed that there was no question of ConocoPhillips buying Lukoil outright.
"We are not planning to sell the company. We are building Lukoil to give it to our children," he told the FT.
The report comes as foreign investors are reassessing the risk of backing Russian firms in the wake of a government investigation into the country's biggest oil firm, Yukos.
The investigation culminated with the arrest on fraud and tax evasion charges of former Yukos chief executive Mikhail Khodorkovsky.
Mr Khodorkovsky's arrest is widely believed to be a politically-motivated response to this support for opposition groups.
But there are fears that the Yukos investigation marks the start of a wider crackdown on private enterprise.