Herbert Smith, Jones Day and White & Case advised jointly on the $3.5bn (£1.79bn) acquisition of a Russian oil producer by Chinese state-owned oil company China Petroleum & Chemical Corporation (Sinopec). It is the largest cross-border investment from China into Russia and the second-largest single foreign investment into the Russian oil sector to date. Herbert Smith's Beijing and Moscow offices linked to advise a Sinopec subsidiary on the purchase of OAO Udmurtneft, itself a subsidiary of TNK-BP. Sinopec formed a joint venture with Russia's state-owned oil company Rosneft, which was advised by Jones Day, for the purchase. White & Case, a regular adviser to TNK-BP, acted for the target OAO Udmurtneft.