The organisation said that the slowing in beer sales experienced by the on-trade for the past year was now feeding through to the take-home market.
Chief executive Rob Hayward said: “The accelerating decline in beer sales is a clear sign of a worsening economy, worried households and weakening spending.
“The downturn has broadened to affect sales through both pubs and supermarkets.
“This trend is symptomatic of the problems infecting the broader economy.”
UK beer sales dropped by 7.2% in the third quarter, a fall equivalent to 1.8 million pints a day.
Sales in pubs, bars and restaurants fell 8.1%.