Friday's Tech Winners & Losers

Technology stocks moved lower Friday, with the biggest plunges coming from two companies that slashed revenue forecasts for the recently ended quarter.

Keithley Instruments(KEI Quote), a maker of electrical test equipment, was sliding 20% after the company lowered its fiscal second-quarter revenue projection. The company now sees revenue of about $33 million for the March quarter, down from an earlier forecast of $37 million to $41 million. Analysts polled by Thomson First Call project revenue of $40.3 million.

Keithley blamed the shortfall on more cautious spending patterns among its customers. Shares were trading down $3.06 to $12.44.

Meanwhile, Semitool(SMTL Quote) slumped 17% after the maker of chip manufacturing tools cut its second-quarter revenue estimate, as well as its full-year target. For the quarter ended March 31, the company expects to post revenue of $51 million to $53 million, down from its earlier outlook of $55 million to $57 million. Analysts, meanwhile, project revenue of $56.5 million.

For all of fiscal 2007, Semitool now sees revenue of $210 million to $230 million, well below its previous guidance of $260 million to $310 million. Analysts project revenue of $273 million. Semitool said that it was hurt by purchase postponements in its target markets. Shares were trading down $2.27 to $10.72.

Planar Systems(PLNR Quote) also cut its guidance, sending shares down 8%. The monitor display maker projects an adjusted loss of 7 cents to 9 cents a share for the quarter ended March 31. Previously, the company forecast a loss of 4 cents to 7 cents a share. Planar sees revenue of $53 million to $54 million, down from a prior view of revenue of $57 million to $61 million. Analysts project a loss of 7 cents a share and revenue of $59.8 million. Shares were down 72 cents to $7.77.