Robinsons and Tango maker Britvic reported weaker sales after Britain's washout start to the summer depressed demand for thirst quenching drinks.
In Ireland, revenues for the quarter were down 15.3% due to continued tough economic conditions, as well as poor weather and tough comparatives.
But the group's revenues were up 0.7% on a year ago in its home market between April and July, down on the previous six months after a 13.3% slide in volume for its portfolio of still drinks, which include Robinsons.
Britvic launched a double concentrate version of Robinsons over the period but found that factors outside its control dented its performance.
It said in an update: "The weather in June had a negative impact on promotional activity around Wimbledon, which is an important focus period for the Robinsons brand."
The Chelmsford-based group, which has the rights to sell Pepsi products in the UK, said volumes of fizzy drinks were down 1.6% as it faced up to promotional activity by rivals.
However, higher than average prices meant revenues from the sector were 4.4% higher than a year ago.
The figures were also impacted by comparisons with strong trading in the comparative period of 2010, when demand was boosted by the football World Cup.