
The data indicated that the poor sales performance could be due to a 38 per cent fall in the popularity of desktops in the US last month.
Apple's desktop unit share was down last month to 15.8 per cent from 17.4 per cent in October and 20.6 per cent in November 2007, noted the research.
While US notebook sales were up in November by 16.6 per cent overall, Apple's unit share decreased from its December figures.
However, NPD pointed to the high Mac sales in October being due to the introduction of new Macbooks.