Diageo's revenues were flat in the second half of 2014, but its profits fell by 18 percent. The two quarters saw the quantity of Guinness sold increase for the first time in six years.

Sales of the stout were up by one percent in Ireland, but overall Irish Diageo sales fell by two percent.

The group's three biggest brands - Smirnoff vodka, Johnnie Walker whisky and Captain Morgan rum - all reported declining sales in the six months ended December 31st.

The company says that the slowdown in the Chinesse economy has been one of the factors affecting sales.

The North American market is Diageo’s biggest and most profitable region; sales in the territory were down by two percent. The company has said that there was a broad slowdown in spirit sales across the US in the run-up to Christmas and that it has struggled to compete with competitors on price.

Chief Executive Ivan Menezes commented on the results: "We have improved our performance during the half and we have again shown: the strength of our brands, which is driving our share gains; our strong innovation capability, which has enabled us to access new growth opportunities; and our focus on cost."