Beer merger will not bring Budweiser, Miller under same roof

To ease concerns the brewing behemoth might get a stranglehold of the U.S. market, SABMiller will sell its 58 percent stake in a venture with fellow brewer Molson Coors for $12 billion.

The combined company — which as yet does not have a name — will also need to address regulatory issues in China, where SABMiller has a leading position with a 49 percent stake in the Chinese beer Snow.

AB InBev is seeking to bolster growth by acquiring SABMiller's businesses in Africa and Asia as changing tastes and the growth of craft beers cut sales in developed markets.

Though AB InBev got SABMiller's main shareholders on board and lined up the largest-ever acquisition debt package, Erik Gordon of the Ross School of Business at the University of Michigan said the deal faces regulatory risks.

SABMiller is the descendant of South African Breweries and has stretched its reach across the continent, betting that Africans will shift to higher quality beers as economic development increases income.

The deal gives the new company 29 percent of the 198 billion liter global beer market — and makes it three times bigger than its nearest rival, Heineken, with a mere 9 percent, said Jeremy Cunnington, the senior alcoholic drinks analyst at Euromonitor International.