Under a contract of guarantee signed in May 2004, Yuganskneftegaz was guarantor on a $1.6 billion syndicated loan that Yukos secured with foreign banks. The new owner of Yuganskneftegaz, state-owned oil company Rosneft, contested the legality of the document, arguing that Yukos had already been faced with tax debt claims twice as much as the loan when the contract was signed.
Yukos lawyers said the lawsuit was groundless because Rosneft held no Yuganskneftgaz shares at the moment of signing. But a Moscow arbitration court granted Rosneft's claim on March 17.
A 76.79% stake in Yuganskneftegaz, Yukos main production unit, was sold by the federal property management fund on December 19, 2004, in lieu of Yukos' tax arrears for 2000 and 2001. Several days later, Rosneft purchased the unit from Baikal Finance Group, the shadowy group that won the auction.