Shares in Russian oil major Yukos plunged yesterday after bailiffs seized its shares in its main production unit, Yuganskneftegaz, for the second time, signalling the state's resolve to dismantle the oil company.

Justice ministry officials, collecting a $3.4 billion (€2.8 billion) tax debt for 2000, said late on Monday they had frozen shares in the oil-producing subsidiary despite a court decision on Friday which ruled that an earlier seizure of the unit was illegal.

Bailiffs earlier said they had plans to sell it.

At one stage, Yukos shares were trading 13.23 per cent lower at 110.20 roubles (€3.07) on Moscow's MICEX exchange, slightly stronger after they were suspended from trade for an hour.

Yukos's volatile shares have regularly been suspended in recent weeks.

"The news is obviously negative as it renews fears of massive asset losses," Troika Dialog said in a research note.

"We are particularly disappointed with the way that the government is handling the news flow on the company. Branches of power are being played against one other, making the whole process a joke, the stock market a casino and analysts' work a nightmare."

The statement came as a shock to investors and analysts as it appeared to say that bailiffs had re-seized Yukos's shares in Yuganskneftegaz almost immediately after the Friday court ruling. That ruling sparked a 17 per cent gain in Yukos stock on Monday.

"The statement said that they did this on Friday, which begs the question as to why they delayed such a price-sensitive piece of news until after the stock markets closed on Monday?" Alfa-Bank strategist Chris Weafer said in a research note released overnight.

The campaign against Yukos is widely seen as punishment for its founder Mr Mikhail Khodorkovsky's political ambitions.