There’s already trouble brewing for the possible merger of the world’s largest beer makers, Anheuser-Busch InBev and rival SABMiller, as the deal is likely to face serious antitrust scrutiny, the Wall Street Journal reports. The two companies together produce nearly one-third of all beer worldwide under a bevy of brands, including Budweiser, Miller, Coors, Corona and dozens of others, and both have big operations here. AB InBev has a brewery in Van Nuys, while SAB Miller has one in Irwindale.