Legacy, headed by Labour Party supporter and benefactor Robert Bourne, bid £125m for the Dome and wanted to turn it into a hi-tech business centre.
A spokesman for Dome minister Lord Falconer conceded that it "will take time" to find a new owner for the controversial London attraction, which closed at the end of last year but still costs just under £1m a month to run.
On Monday a newspaper report suggested the site could remain empty until 2004 as ministers have shelved plans to re-start the selling process until after the general election, widely expected in June.
But Lord Falconer's spokesman said: "We are still talking to interested parties and only when we have finished can we draw up a sale process.
"We are testing the market. There have been more than 100 expressions of interest and the whole process will take time.
"But I don't think this figure of three years is particularly accurate."
Legacy, headed by Labour Party supporter and benefactor Robert Bourne, bid £125m for the Dome and wanted to turn it into a hi-tech business centre.
After this plan was ditched by the government in February, former Dome chief PY Gerbeau then piloted a short-lived bid of his own.
The Times, quoting a "senior Dome source", said a decision on the future of the selling process has now been delayed until the end of June at the earliest.
With several months' consultation, further time for a new preferred bidder to prove their plan's viability and refurbishment work the site could remain closed for three more years, according to the source.
Dome operators the New Millennium Experience Company (NMEC) have confirmed current running costs total just under £1m a month - but say the figure should halve by July.
A spokesman said: "NMEC is still winding down and has finance employees and lawyers closing down contracts.
"After June, a smaller management team will still be retained and there will be maintenance and security costs."