Drinks group C&C said its operating profit before exceptionals for the six months to the end of August fell by 7.9% to €55.1m.
Its half yearly revenues were down 8.1% to €307m, while basic earnings per share rose by 0.7% to 13.8 cent.
C&C said the fall in the value of sterling after the Brexit vote had an adverse impact on reported revenues and operating profits of €24.4m and €2.8m respectively.
The company also said it was seeing some volatility in consumer behaviour across industry on economic uncertainty following the Brexit vote and the subsequent devaluation in sterling.
But the company said its operating profits stabilised in Ireland after a challenging full year 2016.
C&C's group chief executive Stephen Glancey said the business is capable of weathering the current challenges.
"Our confidence in the medium to long term outlook is based on the strength of our key brands, our business model and leading positions in Ireland and Scotland - where fundamentals remain strong," Mr Glancey said.
He also said the company had a growing export business, a broadening portfolio of premium and speciality beers and cider as well as the right partner for its US brands.
In its results statement, C&C said that volumes of its Bulmer cider brand rose by 6%, supported by category growth and commercial initiatives. Tennent's volumes were up 2% in the Scottish market as it continued to regain market share.
It also noted that volumes of its Magners cider brand rose by 11%, while its Magners Original apple brand now makes up 84% of total brand volumes.
During the six month period, its export markets saw 10% volume growth.
It also reported 24% volume growth across its portfolio of premium and speciality beers and ciders - including Clonmel 1650, Heverlee, Menabrea, Drygate and Chaplin and Cork's.
Shares in the company closed 2.5% lower in Dublin trade today.
