Mitchells & Butlers (M&B), which owns All Bar One, Browns and Harvester, has lost £274m because of a failed attempt to spin off property assets.
Last August, M&B was planning a joint venture with property tycoon Robert Tchenguiz, involving up to 2,000 pubs.
It set up financial transactions to protect the venture against changes in interest rates and inflation.
At the last minute, the banks declined to back the venture, leaving M&B to take big losses from the transactions.
The pub operator accepted the resignation of finance director Karim Naffah, but decided to keep on the chief executive, Tim Clarke.
The executive directors will all forego their 2007 bonuses.
In a trading statement, M&B said, "The pub sector is facing some of the strongest challenges it has encountered for many years".
Like-for-like sales rose 0.7% in the past 17 weeks, with food sales compensating for declining alcohol sales.
The credit crunch refers to the effect created when many banks discovered that they held debt based on US sub-prime mortgages, which was of questionable value.
They were suddenly reluctant to lend money, because they were uncertain how much of it they would need to cover their own positions.
M&B's property spin-off collapsed because banks that had previously expressed an interest in the venture decided not to lend money to fund it.
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