Shares of Plexus ( PLXS) were among technology's losers Thursday, tumbling 29% after the electronics-manufacturing services company posted mixed third-quarter results and projected fourth-quarter results below Wall Street's forecast.

For the period ended July 1, the company earned $25.1 million, or 53 cents a share, on revenue of $397.4 million. Results included a penny a share in stock-based compensation costs. Analysts polled by Thomson First Call expected earnings of 53 cents a share and higher revenue of $399.9 million. During the year-earlier period, Plexus reported a loss of $21.5 million, or 50 cents a share, on revenue of $313.7 million. The year-ago results included 66 cents a share in restructuring charges.

Plexus sees fourth-quarter earnings of 46 cents to 50 cents a share, including about 3 cents a share in stock-based compensation costs and 2 cents a share in asset-retirement obligations. The company predicts revenue of $390 million to $405 million. Analysts project earnings of 56 cents a share on revenue of $418.3 million. Shares were trading down $9.83 to $23.77.

Navteq ( NVT) sank 29% after the navigation-systems company posted weaker-than-expected second-quarter results. The company earned $23.8 million, or 25 cents a share, on revenue of $135.9 million. Analysts expected earnings of 28 cents a share on revenue of $142.4 million. During the year-earlier quarter, the company earned $25.3 million, or 27 cents a share, on revenue of $122.8 million. "We faced a number of challenges in the second quarter," Navteq said, "including unfavorable car sales trends and delays in customer product launches, which prevented us from achieving the results we expected." Shares were trading down $9.83 to $23.77.

Shares of Silicon Image ( SIMG) jumped 15% after the chipmaker posted better-than-expected second-quarter results. The company earned $5.8 million, or 7 cents a share. Excluding items, the company earned $16.3 million, or 19 cents a share, beating Wall Street's target by 4 cents. Revenue totaled $70.6 million, compared with analysts' projection of $67.1 million. During the year-earlier period, the company posted adjusted earnings of $10.6 million, or 13 cents a share, on revenue of $50.7 million.

Silicon Image anticipates third-quarter sequential revenue growth of 10%, which would result in revenue of about $77.7 million. Analysts project third-quarter revenue of $73.4 million. The company sees adjusted gross margins of about 57%. For all of 2006, the company now sees revenue growth of 30% to 35%, up from an earlier forecast of 25% to 30%. Shares were trading at $10.70, up $1.40.

Sanmina-SCI ( SANM) slid 9% after the electronics-manufacturing services company posted third-quarter revenue that disappointed investors and cautioned that it may not be able to file its quarterly report on time because of an ongoing review of its stock option practices. For the period ended July 1, the company reported revenue of $2.71 billion, compared with analysts' projection of $2.72 billion. During the year-earlier period, the company posted revenue of $2.83 billion. Sanmina said it won't post its full third-quarter results until it completes its options investigation.

Looking ahead, Sanmina-SCI sees fourth-quarter revenue of $2.7 billion to $2.8 billion. Analysts, however, project higher revenue of $2.83 billion. Shares were off 33 cents to $3.36.

Shares of Covansys ( CVNS) jumped 21% after the information-technology services company posted better-than-expected second-quarter results. The company earned $10.3 million, or 27 cents a share, on revenue of $118 million. Excluding the state and local government consulting practice, the company earned $10.9 million, or 29 cents a share, on revenue of $108.5 million. Analysts expected earnings of 19 cents a share and revenue of $103.9 million. During the year-earlier period, the company earned $9.7 million, or 26 cents a share, on adjusted revenue of $86.4 million. The year-earlier results included one-time items that boosted earnings by $2.7 million during the year-ago period. Shares were up $2.33 to $13.40.

Other technology movers included Symantec ( SYMC), up $1.65 to $17.45; Intel ( INTC), up 16 cents to $17.66; Lucent Technologies ( LU), down 3 cents to $2.08; Sun Microsystems ( SUNW), up 5 cents to $4.32; Microsoft ( MSFT), up 1 cent to $24.38; JDSU ( JDSU), up 1 cent to $2.26; XM Satellite Radio ( XMSR), up 42 cents to $10.78; Sirius Satellite Radio ( SIRI), down 3 cents to $3.93; Applied Materials ( AMAT), up 23 cents to $15.28; and Apple Computer ( AAPL), up 92 cents to $64.79.

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