Viktor Gerashchenko, chairman of Russian oil major Yukos, is a crisis manager known for honing the survival skills vital to steer the firm away from bankruptcy and confrontation with authorities.

Mr Gerashchenko, appointed less than a month ago, said Yukos was suffering from serious internal conflict pitting groups of owners and managers against each other.

Lawyers representing Yukos's incarcerated main shareholder, Mikhail Khodorkovsky, had called for his dismissal last week.

But Mr Gerashchenko saw no legal reason to be sacked. He denounced such calls as "improper".

There were, he said, "groups of influence with an interest in a protracted conflict with the state in order to resolve their personal, mercantile interests. A Yukos board headed by me will oppose these groups by all means."

Core shareholders who backed Mr Gerashchenko's appointment were counting on his experience and connections to reach a settlement with the Kremlin over billions of dollars in tax arrears.

But many say the wry, affable 66-year-old former central banker is failing to deliver the goods. Authorities have so far failed to accept compromise offers put forward by the company.

Mr Gerashchenko said in recent weeks that government ministers were not returning his calls, but now denies any trouble.

"I do not have, nor have I ever had, any problems in communicating with the country's leadership and with heads of particular ministries and government departments," he said.

Mr Gerashchenko was dubbed the worst central banker in history by Harvard economist Jeffrey Sachs for presiding over a 30 per cent fall in the rouble on "Black Tuesday", October 11, 1994.

It was also on his watch that billions of dollars in central bank cash were funnelled through offshore havens into the then-risky government bond market, an investigation later found.

Mr Gerashchenko took the fall for the rouble debacle, but was recalled for a second term after the 1998 financial crash and over four years nurtured Russia's economy back to health.

But he left Russia's banking system unreformed - a drag on development concealed by rapid growth driven by high oil prices.

Mr Gerashchenko rebuffs his critics with dry humour but his comments have raised questions over his loyalty towards Menatep, the holding firm which controls Yukos and is owned by Mr Khodorkovsky, Mr Lebedev and other shareholders exiled in Israel.

"You know the main shareholders; draw your own conclusions," Mr Gerashchenko said when asked who backed him. "Why should I talk to this or that shareholder? Should I go to Israel, or what?"

Since joining Yukos, Mr Gerashchenko has resigned as member of parliament, where he represented the nationalist Motherland party, which argues for higher oil taxes.