Lion Nathan has admitted that sales revenue from its wine business fell by 10% in the final quarter of 2008.
It told shareholders: "The fine wine market has declined dramatically as a result of the current economic conditions, particularly in the UK and US but also Australia.
"The extreme heat and fires in Victoria and South Australia over the summer period are likely to adversely impact the current vintage."
Lion Nathan said it expected its wine results to be "down significantly" on the previous financial year. But since wine only represents about 3% of its profits the business is said to be "robust", and buoyed by solid performances from its beer brands.
Lion Nathan's wine brands include Petaluma, Wither Hills, Tatachilla and Stonier. Its UK distributor is Bibendum.