Exporters and producers are more pessimistic since February's earthquake reduced their ability to sell goods offshore.
A survey of business conditions by the Manufacturers Exporters Association, shows sales were 13% lower in February than they were a year earlier.
Exports dropped by more than a quarter and domestic sales fell 5%.
Business confidence also fell, with a net 13% of respondents pessimistic about conditions.
However, association chief executive John Walley says things could have been worse.