The top after-market NASDAQ Stock Market losers are: BTU International, Quest Software, Key Tronic, QuickLogic, Web.com Group, Oplink Communications, First Solar, OpenTable, Motricity, and Century Aluminum.

BTU International Inc. (BTUI) stock plunged 19.94 percent to $9.96 in the after-market trading, as it guided second quarter revenue below Street view. The company said a delay in planned shipments to a major customer could reduce second quarter revenue to a range of $17 million to $18 million, while Street predicts revenue of $27.13 million. The company also said the timing of shipments of the order might affect its overall rate of growth for the current year.

BTU International reported first quarter earnings of $1.83 million or $0.19 per share, compared to a loss of $293,000 or $0.03 per share last year. Sales surged 48 percent to $25.35 million. Analysts had expected earnings of $0.12 per share on revenue of $25.07 million.

Quest Software Inc. (QSFT) stock plummeted 16.85 percent to $20.98 in the after-market trading, as its first quarter earnings and revenue missed Street view. Profit was $3.6 million, or $0.04 per share, down from $15.6 million, or $0.17 per share last year. Adjusted earnings were $19.0 million or $0.20 per share, down from $24.3 million or $0.26 per share last year. Revenue rose 9.9 percent to $188.2 million. Analysts had expected earnings of $0.29 per share on revenue of $197.92 million.

Key Tronic Corp. (KTCC) stock dropped 11.13 percent to $4.55 in the after-market trading, as its third quarter earnings declined due to increased material, freight and operational expenses associated with the company’s new product mix and program startups. Profit was $724,000 or $0.07 per share, down from $4.4 million or $0.43 per share last year. Results for last year quarter included a net deferred tax benefit of $2.2 million or about $0.22 per share. Revenue grew 23 percent to $63.4 million.

Key Tronic expects fourth quarter earnings of $0.07 to $0.12 per share and revenue of $61 million to $65 million. Moving into the fourth quarter of fiscal 2011, we are seeing some increased demand in the forecasts from our longstanding customers, and we continue to focus on moving the new programs into production. We expect to be generating revenue from 30 EMS customers in the fourth quarter compared to 20 EMS customers contributing to fourth quarter revenue in fiscal year 2010, said Craig Gates, President and Chief Executive Officer of Key Tronic.

QuickLogic Corp. (QUIK) stock fell 9.59 percent to $3.30 in the after-market trading. Loss for the first quarter widened to $878,000 or $0.02 per share from $143,000 or breakeven per share last year. Adjusted loss narrowed to $435,000 or $0.01 per share from $484,000 or $0.01 per share last year. Revenue rose to $5.55 million from $5.43 million.

Web.com Group, Inc. (WWWW) stock fell 9.33 percent to $13.60 in the after-market trading, as its first quarter earnings missed Street view by a penny. Adjusted earnings from continuing operations were $6.39 million or $0.21 per share, up from $3.35 million or $0.12 per share last year. Revenue grew to $39.48 million from $25.13 million, while adjusted revenue rose to $45.1 million from $25.14 million. Analysts had expected profit of $0.22 per share on revenue of $41.44 million.

Oplink Communications Inc. (OPLK) stock tumbled 8.98 percent to $17.33 in the after-market trading, as it guided fourth quarter below Street view. The company expects third quarter adjusted earnings of about $0.22 to $0.28 per share and revenue of $43 million to $47 million, while Street predicts profit of $0.45 per share on revenue of $52.78 million. The company reported third quarter adjusted profit of $10.6 million or $0.49 per share, up from $4.8 million or $0.22 per share last year. Revenue grew 59 percent to $53.5 million. Analysts had expected profit of $0.49 per share on revenue of $53.09 million for the third quarter.

First Solar, Inc. (FSLR) stock slid 8.51 percent to $123.20 in the after-market trading. Profit for the first quarter was $116.0 million or $1.33 per share, down from $172.3 million or $2.00 per share last year. Sales declined slightly to $567.29 million from $567.96 million, mainly due to lower average selling prices. Analysts had expected earnings of $1.16 per share on revenue of $544.37 million.

First Solar still expects full year 2011 earnings of $9.25 to $9.75 per share and net sales of $3.7 billion to $3.8 billion, while Street predicts profit of $9.52 per share on revenue of $3.79 billion. Despite European market uncertainties, First Solar has good visibility into our demand for 2011. We continue to execute our cost roadmaps, invest in new module capacity, build our project pipeline and develop promising new markets around the world, said Rob Gillette, Chief Executive Officer of First Solar.

OpenTable, Inc. (OPEN) stock slid 8.10 percent to $96.50 in the after-market trading, after a surprise management change and first quarter results. The company said chief financial officer Matthew Roberts will be promoted to president and chief executive officer and join the board of directors, effective June 1. He will also continue to serve as CFO until a replacement is found. Meanwhile, Jeffrey Jordan, the company's president and chief executive officer since June 2007, will serve as executive chairman.

Separately, OpenTable reported first quarter earnings of $4.19 million or $0.17 per share, up from $2.52 million or $0.11 per share last year. Adjusted profit rose to $6.77 million or $0.28 per share from $3.43 million or $0.15 per share. Revenue grew 59 percent to $33.71 million. Analysts had expected profit of $0.23 per share on revenue of $33.46 million. The number of diners seated by the company's system surged 55 percent to 22.4 million, while the company's installed restaurant base increased 62 percent to 21,214 as of March 31, 2011.

Motricity, Inc. (MOTR) stock declined 7.10 percent to $11.90 in the after-market trading. Adjusted profit for the first quarter was $1.3 million or $0.03 per share, up from $0.5 million or $0.01 per share last year. Revenue rose to $32.2 million from $29.1 million. Analysts had expected profit of $0.01 per share on revenue of $32.60 million.

For the second quarter, the company expects adjusted earnings of $3.5 million to $4.5 million and revenue of $36 million to $38 million. Motricity's 2-3 year financial targets include annual revenue growth of about 30 percent, and further margin expansion, reaching an adjusted EBITDA margin of about 32 percent and adjusted profit margin of about 25 percent. Street analysts predict profit of $0.10 per share on revenue of $37.40 million for the second quarter.

Century Aluminum Co. (CENX) stock decreased 5.98 percent to $18.56 in the after-market trading. Profit for the first quarter was $25.0 million or $0.25 per share, up from $6.3 million or $0.06 per share last year. Changes to the Century of West Virginia retiree medical benefits program increased quarterly results by $9.4 million with an associated discrete tax benefit of $2.1 million. Sales rose to $326.3 million from $285.4 million. Analysts had expected profit of $0.28 per share on revenue of $335.06 million.