Shares of Dycom Industries ( DY - Get Report) were among technology's losers Tuesday, falling 12% after the provider of specialty contracting services to telecom companies posted fourth-quarter results and issued first-quarter guidance that disappointed investors.

The company posted pro forma earnings of $16.6 million, or 34 cents a share, on sales of $251.3 million. Analysts surveyed by Thomson First Call were expecting earnings of 33 cents a share on sales of $251.7 million. About two weeks ago, the company said earnings would come in at the low end of its previous guidance of 33 cents to 38 cents a share. Dycom said that sales would come in at the low end of its previous guidance of $250 million to $270 million. A year ago the company earned $17.1 million, or 35 cents a share, on sales of $260.8 million.

Looking ahead, Dycom forecast first-quarter earnings of 17 cents to 23 cents a share on sales of $225 million to $245 million. The single-analyst forecast called for earnings of 36 cents a share on sales of $266 million. Shares were trading down $2.65 to $18.60.

Hutchinson Technology ( HTCH) fell 17% after the disk-drive component maker cut its fourth-quarter earnings and sales guidance. The company now expects earnings of 5 cents to 20 cents a share on sales of $150 million to $165 million. Previously, the company said that it would earn 55 cents to 65 cents a share on sales of $165 million to $180 million. Analysts had been expecting earnings of 59 cents a share on sales of $174.9 million. Hutchinson said that soft demand and a shift in product mix hurt its results. Gross margins are now expected to be between 19% and 23%, down from previous guidance of 28% to 30%. Hutchinson plans to release its fourth-quarter earnings on Nov. 1. Shares were recently trading down $5.23 to $26.28.

Shares of ATI Technologies fell 1% after the maker of graphics chips cut its fourth-quarter sales outlook for the second time in two months. The company now expects sales of $465 million to $480 million. In late June the company slashed its sales guidance to $550 million to $580 million, down from previous guidance of $600 million. "This has clearly been a challenging and disappointing quarter for ATI and we are committed to resolving our operational issues," the company said in a statement late Monday. ATI plans to post fourth-quarter results on Oct. 6. After falling by as much as 8% in early trading, shares of ATI were recently down 15 cents to $11.19.

FuelCell Energy ( FCEL - Get Report) rose 6% after the company posted third-quarter results that were better than expected. The company posted a loss of $18.6 million, or 38 cents a share, on sales of $8.7 million. Analysts were expecting a wider loss of 41 cents a share on sales of $6.4 million. A year ago the company reported a loss of $19.2 million, or 40 cents a share, on sales of $8.1 million. Shares were trading up 59 cents to $10.13.

Shares of QLogic ( QLGC) fell 5% after the company said it would sell its hard-disk drive controller and tape-drive controller business to Marvell Technology Group ( MRVL - Get Report) for $225 million. The deal consists of $180 million in cash and $45 million in Marvell stock. QLogic said the deal would enable it to focus on the higher growth SAN infrastructure component market.

QLogic also said that its board has authorized a $350 million stock buyback plan, which will be conducted over the next two years. Shares of QLogic were recently trading down $1.90 to $33.74.

Other technology movers included Microsoft ( MSFT - Get Report), down 5 cents to $27.10; Cisco ( CSCO), down 15 cents to $17.49; Intel ( INTC - Get Report), down 21 cents to $25.52; Sun Microsystems ( SUNW), down 5 cents to $3.66; Oracle ( ORCL), down 10 cents to $12.98; and Lucent Technologies , down 4 cents to $3.05.