Molson Coors Brewing, the North American beer company, has declared its interest in a potential takeover or break-up of Foster's after admitting it had quietly built a near 5 per cent stake in the Australian beer and wine group.

"Foster's has not been informed of the precise extent of Molson Coors' interest in the company nor their intentions with respect to that interest," the Australian group said in a statement in Australia early yesterday.