Chip-equipment maker

KLA-Tencor

(KLAC) - Get Report

was down 3% in preopen

Island

trading after it warned that revenue for its third quarter would be 8% to 10% below its previous estimates and earnings will fall short of the previous forecast of 58 cents per share.

The company cited slowing demand and excess inventories at its customers.

Robertson Stephens

downgraded the stock to long-term attractive from buy and cut its 2001 and 2002 earnings estimates.