R20, the investment vehicle of Iranian property tycoon Robert Tchenguiz, has admitted it has been looking to mount a bid for Mitchells & Butlers (M&B).
In an announcement, R20 admitted it has "been discussing with a number of parties the possibility of forming a consortium to approach the board of M & B in relation to a potential offer for Mitchells & Butlers".
The statement added: "These discussions are at an early stage. As a result there can be no certainty that an offer will be made."
The interest in M & B follows R20's narrow failure to buy Spirit Group last November.
R20 already owns Laurel Pub Company, which around 400 managed pubs, and Globe Pub Company, which has around 440 tenanted pubs.
City analysts say any Tchenguiz led consortium could expect to pay around £4billion for the chain.
In December, Tchenguiz lost out to Punch Taverns in a £2.7bn battle for the Spirit pub group.
Spirit fetched about 10.3 times annual earnings.
Priced similarly, Mitchells & Butlers would command a price tag just shy of £4.2bn, including £1.6bn of debt.
That equates to about 540p a share.
News of the interest sparked a massive climb in M&B's share price.
Shares jumped by 21% or 87.5p to 500.5pence following the announcement.