Suntory, which owns whisky business Morrison Bowmore in Scotland, is thought to be aiming to raise up to 500 billion yen (£3.7bn) from the initial public offering.
Damian McNeela, analyst at Panmure Gordon, wrote in a note for clients: "While unconfirmed at this stage, it is thought that proceeds could be used to fund international acquisitions.
"Suntory is already a Pepsi bottler and licences Orangina to AG Barr.
"If Suntory were to consider a move into the UK then we would expect its interest to fall on the enlarged Barr Britvic Soft Drinks company."
Suntory plans to retain a sizeable stake in Suntory Beverage and Food, whose businesses include making tea and juices, and distributing chilled drinks for Starbucks, sources said.
Britvic bottles Pepsi in the UK while Suntory undertakes the role in Japan, and recently entered into a joint venture with Pepsi in Vietnam.
Mr McNeela said the acquisition of Barr Britvic, which will have its registered headquarters in Cumbernauld, could provide a platform for further consolidation of Pepsi's bottling operations.
Shares in AG Barr rose 3.5p, or 0.73%, to 485p.
Suntory is Japan's number two soft drink maker. As well as owning Scotch whisky brands such as Auchentoshan and Glen Garioch, it has Japanese whisky brands including Yamazaki and Hibiki.