SABMiller has suspended work on integrating its operations with those of Anheuser-Busch InBev while it reviews its sweetened bid, raising concern about completion of the 79 billion pound ($104 billion) takeover.

AB InBev increased its cash offer for SABMiller Tuesday to 45 pounds per share to blunt a revolt by investors who had seen the relative value of their payout plummet as the pound declined following Britain's vote to leave the European Union.

SABMiller CEO Alan Clark said in memo to employees that all convergence planning has been "paused" and there should be no contact with representatives of AB InBev, the maker of Budweiser, as the board considers the offer.

Clark says he recognizes the move will cause "internal and external speculation" and he'll update workers as soon as possible.