Brazilian billionaire Jorge Paulo Lemann and his partners in private equity firm 3G Capital are considering a potential bid for Diageo PLC - the owners of Guinness.
Shares in Diageo gained nearly 9pc to just bring it to €19.14 this morning as news emerged of the possible deal in the Brazilian newsweekly Veja.
This was the biggest gain since November 2008 valuing the firm at about £48bn.
Lemann, who is Brazil's richest man, and partners Marcel Telles and Beto Sicupira, are in the initial stages of studying a buyout offer for Diageo, Veja reported in its Radar column, without saying how it obtained the information.
US-listed shares of Diageo jumped 8.7pc on the report to close at $118.0 in heavy trading, the biggest gain in six-and-a half years.
Diageo had no immediate comment. Efforts to reach 3G Capital representatives in Rio de Janeiro were not successful.
London-based Diageo produces Guinness as well as some of the world's leading beverage brands, including Johnnie Walker whisky, Smirnoff vodka, Tanqueray gin and Don Julio tequila.
Lemann has embarked on a shopping spree in recent years that included buying Burger King from Diageo in 2010 and buying HJ Heinz Co in 2013 in partnership with US billionaire Warren Buffett.
Harvard-educated Lemann is the chief investor and strategist at 3G Capital.