Tom Bawden: Relief at end of TNK-BP relationship from which both partners were desperate to escape

Anyone who has been following the TNK-BP Russian joint venture can only conclude that the two partners desperately needed a divorce.

That happened in no uncertain terms yesterday when not one but both of the venture's 50 per cent shareholders sold their stakes to Rosneft, the Russian state oil giant.

Severing ties with the AAR quartet of Russian billionaires who own the other half will come as a welcome relief for BP as a company, and for chief executive Bob Dudley in particular. He was famously forced into exile in 2008 during a previous role as head of TNK-BP, citing a campaign of harassment, in what was only one in a long line of tense situations.

With BP close to finalising a settlement of around $15bn over the Gulf of Mexico oil spill in 2010 that would absolve it of criminal damages and further civil claims, the company looks well on the way to resolving the two big issues that have dogged it in recent years.

Shareholders could do with some good news. BP's share price remains about 30 per cent below its pre-spill level, while the dividend is languishing at barely half what it was at that point. In those days, it accounted for £1 in every £6 paid to UK pension funds. Analysts were forecasting that yesterday's cash windfall would enable BP to pay a special dividend, with some suggesting it could be as high as $10bn.

But questions remain. The TNK-BP venture was an incredibly good earner, paying BP a total of $19bn in dividends since it was set up in 2003 and representing around a fifth of the group's profits.

And although climbing into bed with Rosneft will allow BP to retain a substantial presence in the world's most promising oil frontier, partnering with the Kremlin is unlikely to be a walk in the park, as evidenced by its reputation for being a stingey dividend payer. BP has improved its circumstances, but it will be a while before we have a clear sense of by how much.