DTZ was yesterday forced to announce that its shares were virtually worthless after bids for the property consultant attached little or no value to its equity.
As a result, the company's already battered shares plunged 87 per cent yesterday to 2.85p.
The shares had already more than halved since mid-May, when they stood at 51p after SGP's interest was announced. After yesterday's price collapse, the company's market value was just £7.8m last night – down from £2bn in a little less than five years.
DTZ invited fresh bids last month after long-running talks with its biggest shareholder, Saint George Participations (SGP), failed to produce an offer for the whole of the company.
More suitors came forward after SGP withdrew but DTZ's £6m of debt in effect wiped out any value attached to the company. DTZ, which advises on large property deals, was required to announce the valuation placed on the business to make sure there was no false market in its shares.
In its statement, DTZ said: "Based on the valuation of DTZ derived from proposals received to date, however, and, given the level of debt within DTZ, there is minimal value, if any, that may be attributed to the ordinary shares of DTZ, although the exact value is uncertain."
The company said the sale process was continuing and that it was examining other options.
Its chief executive, John Forrester, said last month the board was considering a rights issue to cut debt alongside putting itself up for sale. He admitted then that DTZ had been losing business during its long talks with SGP and its future looks no more secure now.
The deal would have seen France's SGP take the company private and then merge it with the real estate arm of the French bank BNP Paribas.
The takeover fell apart amid fears about French banks' exposure to the eurozone crisis.
DTZ, one of the most recognised names in the property business, suffered a terrible recession because of its emphasis on commercial real estate such as shopping centres, where deals have dried up.
DTZ also lost its former chief executive, the former Barclays high flier Paul Idzik, and its finance director, Robert Rickert, earlier this year.
They slashed costs and raised fresh capital from shareholders but quit when the board refused to issue an ultimatum to SGP during five months of negotiations.