It said volumes of cider had remained flat over the six months to 31 August, while its spirits were down 15%.
A 2% decline in British sales of Magners was offset by growth in Northern Ireland and other markets.
Chief executive John Dunsmore said: “Following a positive start to the first half, trading conditions in August and September have been more challenging. However, we remain on track to deliver on the objective of stabilised volumes and a full year operating profit outcome in line with our stated guidance.”
Dunsmore said C&C would be reviewing its marketing strategy following the group’s £180 million acquisition of the Tennent’s lager brand from AB Inbev, which he called “a great opportunity to strengthen our route to market and broaden our product portfolio”.
A statement said: "The market dynamic is one of continued off-trade expansion relative to the on-trade. C&Cs channel volume trends reflect this dynamic with off-trade volume growth and on-trade decline."