LONDON—Anheuser-Busch InBev NV is talking to banks about financing what could be a roughly £75 billion ($122 billion) deal to buy global beer rival SABMiller PLC, according to a person familiar with the matter.

A tie-up between the world’s two largest brewing companies has been rumored for years, but a revival in global merger activity this year has sparked renewed speculation about a deal. AB InBev isn’t in active discussions with SABMiller UK:SAB , said the person, explaining the company is waiting to line up its financing before making a formal approach.