Russian energy firm Yukos, which pumps 2 per cent of the world's oil, warned yesterday that it could be forced to halt production within days under an order from bailiffs who are trying to claim billions of dollars in unpaid taxes.

The statement sent New York light crude futures surging to an all-time high of $43.05 per barrel, while Yukos shares plunged more than 24 per cent in Moscow, where analysts said Russia's biggest oil firm might not survive a controversial legal clash between its founder, Mr Mikhail Khodorkovsky, and President Vladimir Putin.

In a letter to Russia's justice minister, Mr Yuri Chaika, Yukos said bailiffs had demanded an immediate halt to sales of company property at key production units. Under Russian law, "company property" includes products for sale - in this case, most of the 1.7 million barrels of crude that the firm pumps every day.

"It must be noted that the process of pumping oil into the... pipeline system cannot be ceased without stopping production," the letter said.

Yukos pumps more oil than Libya, and the latest threat to its operations sparked a sharp reaction from markets that are closely monitoring a firm that could be driven into bankruptcy over a tax bill that may eventually top $10 billion.

Yukos' chief executive, Mr Steven Theede, also said yesterday that the courts' continuing refusal to allow the company to sell assets to pay its bills meant that shipments to world markets could be severely compromised next month.

Mr Chaika dismissed the warning, and said Yukos was trying to "blackmail" the authorities with claims that its legal and financial woes would eventually lead to redundancy for at least 15,000 workers and unpaid wages