It emerged last week that Punch was in the early stages of considering whether to make an approach for the All Bar One and O'Neills owner after being approached by M&B shareholders.
However, reports that Punch had begun any discussions externally were quashed yesterday.
"Punch notes the current speculation regarding Mitchells & Butlers and confirms that it is not in discussions with M&B, or any M&B shareholder, regarding any offer or merger," the company said
The statement followed a denial on Saturday from M&B after one report said that the two companies were discussing a merger.
Analysts are expecting M&B to report pre-tax profits in the region of £196m on Thursday, against £208m in 2006. The group will also update investors on its plan to launch a £4.5b joint property venture with Robert Tchenguiz.
By Daniel Thomas