Both Punch and M&B joined the FTSE 100 in April after rising property prices boosted their market capitalisation.
However, as the credit crunch hits home heightening lending worries and creating concern that the general public will reign in spending, investors' sentiment towards the two operators has changed.
M&B has suffered the most with its share price falling 20% in the past three months after an aborted deal with investor Robert Tchenguiz over a £4.5b property joint venture.
The Harvester and Ember Inns operator has taken a £155m exceptional cost after the deal stalled in September.
Enterprise Inns remains the only pub operator in the FTSE 100 after this morning's shake-up.
By Christopher Walton
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