The news emerged as PPP administrator Ernst & Young submited its plans for Metronet’s absorption into the Mayor’s transport department Transport for London (TfL).
Research by merchant bank Rothschild found that financial institutions would have approved loans for private bids, according to lead administrator Alan Bloom.
But Bloom claimed all interested parties were soon put off by the stringent requirements attached to the sale.
"[I had to] demonstrate to London Underground's satisfaction that any third party purchaser would be able to meet all of the obligations under the PPP," said Bloom.
Metronet's work programme was severely delayed when it went into administration, so it would have been very difficult for a new owner to meet the contractor's agreed PPP deadlines (NCE 12 March).
Metronet will now transfer to TfL at a date to be determined in a court hearing on 23 May. Metronet shareholder Balfour Beatty's track supply contracts have been amended. So it now works on a "pain share/gain share" basis.
Another Metronet shareholder, Bombardier, will continue as fleet supplier, but its contract has been amended to exclude train maintenance.