Friday's Tech Winners & Losers

Updated from 1:16 p.m. EDT

Tech stocks slipped with the wider market Friday, weighed by a selloff of Network Appliance(NTAP Quote), following disappointing guidance.

The maker of data storage devices slumped 20%, after lowering its outlook for its fiscal first quarter, which ended last month, despite being upgraded by Citigroup. The company, which is expected to report final earnings results for the quarter Aug. 15, said it expects to earn 19 cents to 20 cents a share, excluding one-time items, down from its previous guidance of 24 cents to 25 cents a share. Analysts polled by Thomson Financial expect 24 cents a share. Citigroup, however, upped the stock to buy from hold. Investors didn't share the firm's optimism, sending shares down $5.74 to $22.97.

Network Appliance helped drag down the Nasdaq 100 more than 48 points to 1918.56.

BigBand Networks(BBND Quote) was plummeting 27.8% after swinging to a quarterly profit, but lowering its full-year outlook. The company, which offers platforms that allow cable companies to offer video, voice and data over a variety of networks, earned $1.7 million, or 2 cents a share, vs. $581,000, or 5 cents a share, in the year-ago period.

BigBand said it expected net revenue of between $225 million and $230 million and earnings per share of between 28 cents and 33 cents, excluding items. Analysts polled by Thomson Financial expect revenue of $32.2 million and earnings of 32 cents a share. The stock fell $3.88 in Friday trading, to $10.10.

Silicon Image(SIMG Quote) was sinking 25.3% after Longbow downgraded the chipmaker to neutral from buy. The firm's move came a day after the company, whose chips are used in digital imaging products like computers and DVD players, showed sliding second-quarter profits. Silicon Imaging earned $4.4 million, or 5 cents a share, compared to $5.8 million, or 7 cents a share, in the year-ago period. Shares fell $1.78 to $5.26.

Taleo(TLEO Quote) shares advanced 4.8%, after the software maker reported a narrowed second-quarter loss. Excluding items, the company earned $2.8 million, or 10 cents a share, vs. a loss of $192,000, or a penny a share, in the year-ago period. Analysts polled by Reuters expected earnings of 9 cents a share. Taleo stock was on the upswing $1.04 to $22.88.

Audible(ADBL Quote), which offers digital content like books, newspapers and television shows online, climbed 5.7% after reporting a narrowed second-quarter loss. The company lost $125,000, or a penny a share, compared to $2.2 million, or 9 cents a share in the year-ago period. Analysts polled by Thomson Financial expected a loss of 4 cents a share. Audible shares gained 62 cents to $11.51.