DuPont Photomasks


was down 8.7% in preopen


trading, after it warned that its third-quarter earnings per share would be 53 to 66 cents, below the Street's estimate of 79 cents, though up from 40 cents a year ago. The chip equipment maker cited the slowdown in the semiconductor industry.



, another chip equipment maker, was down 1.6%, after it warned that the industry downturn could hurt its second half results.