If the deal goes ahead it would create a global super-brewer that would dominate the world’s beer supply.
Based on current share prices, the deal is estimated to be worth around US$250 billion (£161bn), and AB Inbev is expected to have to divest holdings in some markets to get regulatory approval.
The move is believed to be a response to the growing popularity of craft brews.
A statement by AB Inbev’s board said: “AB Inbev confirms that it has made an approach to SAB Miller’s board of directors regarding a combination of the two companies. AB Inbev’s intention is to work with SAB Miller’s board toward a recommended transaction.
“There can be no certainty that this approach will result in an offer or agreement, or as to the terms of any such agreement.”
SAB Miller said: “Anheuser-Busch Inbev has informed SAB Miller that it intends to make a proposal to acquire SAB Miller. No proposal has yet been received and the board of SAB Miller has no further details about the terms of any such proposal.
“The board of SAB Miller will review and respond as appropriate to any proposal which might be made.”
AB Inbev must make a formal offer for the company by October 14. In the meantime SAB Miller has advised its shareholders to hold onto their shares and take no action.