SABMiller moved forward the appointment of its new chief executive as it revealed that its executive chairman, Graham Mackay, has been diagnosed with a brain tumour and underwent surgery earlier this week.
The chief operating officer, Alan Clark, was due to succeed Mackay as chief executive in July this year, but treatment of Mr Mackay's tumour means the board have decided to accelerate his promotion.
SABMiller's deputy chairman, John Manser, praised Mr Mackay for his "immense contribution to making SABMiller what it is today" and said the board's thoughts and prayers are with him and his family.
Mr Mackay has been chief executive of SABMiller, which makes beers such as Peroni and Pilsner Urquell, since its listing on the London Stock Exchange in 1999 and is also the brewer's executive chairman. The brewer said Mr Manser will become acting chairman while the South African receives treatment.
In a note to employees, Mr Mackay said that SABMiller would be in "excellent hands" once Mr Clark took over the chief executive role and said he was "inexpressibly proud" of the company, adding: "I certainly do not expect there to be any impact from this development on [SABMiller's] operations or strategic direction, which will continue to run as normal."