Tony Hayward, the chief executive of BP, has held a meeting with Mikhail Fridman, the billionaire Russian investor who is one of three owners of AAR, the oil giant's partner in its troubled TNK-BP venture.
The talks, in Prague on Wednesday, are the first very limited sign of any compromise in the row that has engulfed TNK-BP in recent months, and will encourage investors in BP who have become increasingly concerned about the company's Russian operation.
Last week, Robert Dudley, the chief executive of TNK-BP, had to leave Moscow after the Russian authorities refused him a work permit. Mr Dudley, who has faced calls from AAR for his resignation and is now working from a secret location in Europe, did not attend the Prague meeting, though BP has repeatedly insisted it remains supportive of him.
One source close to the talks said that no deal had been reached, but that the meeting itself was "a step in the right direction". While Mr Hayward has met his opposite numbers at AAR in recent months, this week's meeting was held specifically to discuss the row between the partners.
AAR is arguing that the board of TNK should choose a new chief executive to replace Mr Dudley, with a candidate selected who is not a representative of either itself or BP. However, the oil giant has rejected this call and says it is entirely happy with Mr Dudley's performance.
Nevertheless, without some compromise from one side, the dispute looks almost impossible to resolve. In the meantime, executives at TNK-BP face a series of difficult court hearings over allegedly illegal labour practices, as well as a civil action contesting the legality of the current board set-up.
BP alleges that many of the company's legal problems are part of a campaign of harassment being orchestrated by AAR. The Russian group vehemently denies this.