The stake had been valued at $61.6 million and was one of the largest privatisation offers planned under a new sell-off programme spanning the next two years. "A cabinet order has put the tender off until the end of this year," the source said.

The Chkalov plant announced the tender in September, when it said that the winner would be named by the end of 1998.

Plant officials had said tender invites were sent to 33 foreign firms, including British Aerospace, Boeing, Germany's Hobas AG and Wemex Handel GmBH, US Citibank, Russian's Inkombank and the European Bank for Reconstruction and Development (EBRD).

But the source said there had been little interest from those invited, forcing the tender's postponement. The announcement is the latest sign that Uzbekistan's privatisation programmemay not live up to expectations.

The biggest single stake on offer is 46.5 per cent of shares in the Almalyk copper and zinc plant, valued at $478 million. The bid deadline was originally set for January 15, but has been delayed by six weeks, officially to give foreign companies more time to value the company.

But analysts based in the arid Central Asian state of 23 million suggest that a lack of interest in the plant, amid record low world metal prices, may be the chief cause.

Uzbekistan has adopted an increasingly isolationist economic policy since 1996, but has been forced to open its doors to foreign companies through privatisation to relieve a worsening cash shortage as values for key exports cotton and gold slump.

The Chkalov plant, which produces wide-body cargoIlyushin-76 aircraft and 52-seat Ilyushin Il-114 passenger planes, was made into a joint-stock company in 1996.

Sales have ground to a virtual halt as traditional markets in the former Soviet Union dry up. In 1997 Chkalov offeredinvestors a 14 per cent stake, but negotiations were deadlocked because the government said its assets were undervalued.

In May 1998 the State Property Committee re-evaluated the company, saying it was worth $246.4 million. The state owns 51 per cent of Chakalov, the workers 10.6 per cent, the state-owned National Bank for Foreign Economic Activity and the Foreign Economic Relations Ministry each hold a 6.7 per cent stake.