Speaking in Germany about the sale of Yukos' main oil assets to mystery investor Baikal Finance, Russian President Vladimir Putin said China National Petroleum Corp., which currently has a cooperation arrangement with Russia's state gas monopoly Gazprom, could have a role in managing Yugansk, the principal oil asset of the stricken energy company. "We do not rule out that CNPC may take part in working on this asset as well," Putin was quoted as saying by Reuters. Putin declined to identify the owners of Baikal Finance, which made the US$9.4bn bid. The company does not own any oil wells but its principals are said to be experienced oil industry people. Yukos said it would mount a challenge to roll back the sale on the grounds that it violated US bankruptcy law.