The company pledged to make a first payment of US$2.5 billion this July, with further instalments over the next two years, secured against Yukos' 35% stake in Sibneft, the oil group with which it tried to merge last year, which is worth more than US$4billion.

The bold move puts the onus back on government officials to react if they plan to avert Yukos' move into bankruptcy triggered by a court ruling this month for US$3.4bn in back taxes and penalties for 2000, combined with a freezing order preventing the company from selling assets to raise the money.

Last week former Yukos CEO Mikhail Khodorkovsky, proposed giving up his stock in the company to settle the tax claim, however on Friday Russian finance minister Alexei Kudrin said Yukos had run out of time for striking a deal with the government on restructuring the tax bill for 2000, making asset seizures inevitable.

Government marshals have begun a search for Yukos' assets, issuing a nationwide alert to customs officials and border guards to bar the oil firm from smuggling the share registries of its Siberian production units out of the country.

When marshals tried to seize those registries at the company's share registrar last week, they found that Yukos had already shifted them to its production units.

If the government doesn’t get access to the registries, a blocking order cannot be put on transferring ownership of the production units out of Yukos, which would leave it as an empty shell.

Khodorkovsky’s trial is due to restart today.