Today's announcement followed one in July that the firm would take an £845m hit after looking at 75 per cent of its agreements.
Pre-tax losses for the first half of 2017 topped £1.15bn, Carillion said today.
Interim boss Keith Cochrane said Carillion needed to "take on the chin" all of its problems, adding the firm need to "stop doing things that didn't add value".
Here's how City analysts reacted.
Joe Brent of Liberum reckons Carillion has more debts than the business is worth. In a note this morning he estimated the firm's "enterprise value" is £1.6bn. But he estimated total debts were more, some £2bn.
Brent also summarised his key concerns.
Five major "headwinds" facing Carillion
Carillion has managed to persuade its banks to lend it a further £140m under what is known as an RCF - equivalent to an overdraft for companies, and perhaps just as pricey.
Despite the write-downs, Carillion said it is operating within the parameters, or covenants, that would otherwise allow them to take control. But Andrew Gibb of RBC questioned whether this could continue.
"It has agreed a further £140m with banks and thinks it will be in compliance with covenants," he said.
However, it admits that self-help will not be enough to get to its leverage target of 1-1.5x by end 2018 and therefore the Board is considering other options, including raising equity. Clearly far too many uncertainties at present to take a firm view, but this will be a long road to recovery.
Hargreaves Lansdown senior analyst Laith Khalaf highlighted the firm's pensioners will "take some strain".
Carillion announced £80m of savings by cutting discretionary increases to retirement payouts. And the firm reckons it can cut a further £120m by adjusting annual inflationary increases by linking to the lower consumer price index rather than the current retail price index.
It looks like Carillion employees, past and present, are going to take some of the strain of the current crisis enveloping the company, which is planning to water down their pension benefits to rise at a lower rate of inflation, subject to trustee approval, said Khalaf.
This would bring members into line with the public sector and some other private sector schemes, though such changes are never welcome, particularly when they are prompted by disappointing business performance.
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