Turners Auctions says it is not holding out for a pre-Christmas surge in used-car sales.
The car auction firm expects its 2010 profit will be about 9% below last year's.
Turners made $3.3 million last year, and is forecasting $2.9 and $3.1 million this year.
The company says the used-car market has been subdued in the past three months, and the GST rise and disruption from the Canterbury earthquake have made matters worse.
Chief executive Graham Roberts says he expects buyer caution may continue until at least the end of the year.