Brewing giant Anheuser-Busch InBev has said it had made a takeover move for SABMiller.
The combined value of the two firms is likely to be at least $230bn.
AB InBev's brands include Budweiser, Stella Artois and Corona, while SABMiller owns Peroni and Grolsch.
If the deal is successful, the merged company would produce one third of the world's beer.
AB InBev said it had approached SABMiller's board about a ‘combination of the two companies’.
However, it added that there was no certainty the approach would lead to an offer or an agreement.
Earlier, SABMiller said it had been informed that AB InBev was planning to make a bid, but that it had no details as yet.