The 1% decline in Q4 like-for-like sales reported by Mitchells & Butlers (M&B) this week impacted the M&C20 Index, which fell by 1.3% to 1,148.32, to marginally underperform the FTSE all share, which declined by 0.9% to 1,014.49.

The M&C20 Index fell 15 points, of which a 4.9% drop in M&B’s shares contributed 10 points.

M&B’s performance led Simon French at Panmure Gordon to downgrade his earnings-per-share forecast for Mitchells & Butlers (M&B) following a “disappointing” trading update. French, of Panmure Gordon, reiterated his Sell recommendation and 310p Target Price, implying a 24% potential downside.

The decline in M&B’s performance in the first three weeks in September also had a knock-on affect on Spirit’s share price, which fell 5.9% over the week. The company reports its q4 update on 22 October and Jamie Rollo at Goldman Sachs said: “We will be interested in current trading given M&B said September had been weak across the board as consumers reined in spending after a summer splurge.”

Despite Richoux reporting EBITDA growth from £660,000 to £740,000 in the 28 weeks to 14 July this morning, its shares fell by over 12%.

Essenden was the biggest climber, up 31%, as it reported a 0.7% increase in like-for-like sales for the 26 weeks to 30 June 2013, with EBITDA up 24% to £2.9m earlier this week.

The slide in M&B’s shares saw Greene King leapfrog it to take first place in the order of the value of market capitalisation, while Domino’s has moved past JDW and Marston’s into fourth place. The top six are: Greene King, M&B, TRG, Domino’s JDW and Marston’s.