BP (NYSE:BP) says it has received “unsolicited indications of interest” to purchase its 50% stake in the Russian oil company TNK-BP.

A joint venture between the British oil company and AAR, a group of Russian oil investors, TNK-BP currently accounts for 29% of BP’s total oil production and 27% of its oil reserves. The company’s share in the joint venture is valued at about $15 billion, the Associated Press said.

Shares of BP rose more than 1% in an otherwise down market in Friday afternoon trading in New York.

In statement today, BP indicated that it’s interested in selling its share in TNK-BP, but said discussions were at a preliminary stage. Relations between BP and its Russian partners were strained after AAR prevented BP from forming an alliance with rival Russian oil producer Rosneft.

In the wake of that, BP reportedly offered $27 billion to purchase AAR’s share of the company. AAR demanded $35 billion in addition to part of any BP deal with Rosneft.

TNK-BP ranks as the third-largest oil company in Russia, with a market cap of $31.5 billion on the MICEX exchange. Earlier this week, CEO Mikhail Fridman resigned abruptly. Fridman is a member of AAR.

BP would not disclose any information regarding the identity of the potential buyer of its share in the company.

Representatives of AAR declined to comment on the BP announcement, though AAR members had previously told the press they would be interested in boosting their ownership of TNK-BP.