The detained head of Russia's oil giant YUKOS and newly merged YukosSibneft says he has resigned as CEO of the two companies.
Mr Mikhail Khodorkovsky said: "I am leaving the company. I am sure that a highly professional and close team of experienced managers with the support of the board will successfully cope with the task of globalisation of YukosSibneft's business," he said in a statement this afternoon.
The two firms are at the centre of a confrontation between the Kremlin and big business.
Mr Khodorkovsky's resignation comes several days after he was jailed for fraud and tax evasion - in what many Russians see as politically motivated charges.