Financial magazine Wirtschaftswoche cited unnamed investment bankers as saying that potential buyers of Germany's leading petrol station network with 2,500 outlets included France's Total, European rival Avia and Russia's Rosneft.
Rosneft has already signalled its interest to BP, which faces a colossal bill from its catastrophic Gulf of Mexico oil spill, in supplying Aral petrol refined from Russian oil, the weekly said.
Rosneft is also eyeing up refineries owned by BP in northern Germany, the magazine added in a pre-release of an article to be published on Monday.
BP chief executive Tony Hayward said he was stepping down on Tuesday, following a string of gaffes as the public face of the firm in its three-month fight to stop oil leaking into the Gulf of Mexico.
BP also said it was putting aside more than $32 billion to cover the cost of the spill, and reported a record second-quarter loss of $16.9 billion.