A Gazprom statement on Tuesday said the Russian government was making other plans to boost its stake in the company. A full merger had been expected to allow the Russian government to gain a majority stake in Gazprom, while allowing the remaining shares to be available for purchase by foreign investors.

The Interfax news agency quoted the Russian Economic Development Ministry as saying Rosneft shares would still be available through an IPO, in order to meet debts incurred by purchasing Gazprom shares for the now-dead merger.

Merger plans had been complicated by Rosneft's acquisition late last year of Yuganskneftegaz, the main production unit of the now bankrupt Yukos oil company, which the government ordered auctioned off to meet part of Yukos' multi-billion-dollar tax bills. Previously unknown firm Baikal surprisingly won the Yuganskneftegaz auction, with a bid of US$9.4 billion, though Baikal was later acquired by Rosneft.

Meanwhile, former Yukos boss Mikhail Khodorkovsky remains in jail. The reading of the verdict, in his politically charged trial on fraud and tax evasion, has been suspended amid rumours that it could be weeks before a firm statement of guilt or innocence is issued.

Lawyers for Russia's one-time wealthiest man are reported as saying the phrasing of much of the reading so far makes a guilty verdict certain, but there are signs of a lighter sentence than the 10-year term demanded by prosecutors.

The trial of Khodorkovsky - who once commanded a fortune estimated at US$15 billion - has damaged the reputation of the Russian judicial and business systems. US State Department spokesman Richard Boucher on Monday said the case had shaken overseas confidence in Russia.

The ITAR-Tass news agency has reported that the reading of the verdict so far had not addressed one of the seven charges - that Khodorkovsky and co-defendant Platon Lebedev acquired a large stake in a lucrative fertiliser company by rigging an auction. If the charge is dropped it could mean a lighter-than-expected final sentence.

In the courtroom Judge Irina Kolesnikova, reading aloud and alternating with two associates, has finished a summary of what has been established in the case - that Khodorkovsky and Lebedev had committed six of the seven charges they face. There is still to be a summary of witness testimony before a final verdict and sentencing is delivered.

The market value of Yukos, once as much as US$40 billion, has plunged to just US$2 billion, costing shareholders billions of dollars and disturbing foreign investors who think Russian President Vladimir Putin ignored property rights in taking control of assets in the strategically important energy sector.