Updated from 1:03 p.m. EDT

Shares of Primus Telecommunications ( PRTL) were among the worst-performing technology stocks Friday after the company swung to a second-quarter loss that missed analysts' expectations and warned that third-quarter results would also fall short .

The telecommunications company posted a second-quarter loss of 17 cents a share on sales of $331.6 million. Analysts polled by Thomson First Call had expected it to post a profit of 10 cents a share on sales of $347.7 million. A year ago it earned 21 cents a share. Looking ahead, it expects a third-quarter loss of $8 million to $9 million on sales that are flat vs. the just-ended second quarter. Analysts had expected it to post a profit of 12 cents a share on sales of $356.9 million. Shares of Primus Telecommunications traded down $1.70, or 50.8%, to $1.65.

Conexant Systems ( CNXT) fell after it reported in-line third-quarter results but warned that fourth-quarter results would fall short of expectations. Excluding items, the networking company earned 2 cents a share on sales of $267.6 million, which matched expectations. Looking ahead, however, it expects fourth-quarter earnings of break-even to 2 cents a share on sales of $250 million to $255 million. Analysts were looking for 3 cents a share on sales of $276 million. Shares of Conexant Systems traded down 30 cents, or 15.9%, to $1.59.

Shares of Sapient ( SAPE) rose after the company reported better-than-expected second-quarter earnings and sales. The technology services firm earned 4 cents a share on sales of $64.5 million . Analysts had expected it to earn 2 cents a share on sales of $61.1 million. A year ago Sapient earned 1 cent a share on sales of $58.9 million. The company said that second-quarter performance was strong in all areas of its business. Shares of Sapient traded up $1.69, or 32%, to $6.97.

NetGear ( NTGR) rose after it posted better-than-expected second-quarter earnings results and offered a better-than-expected third-quarter sales outlook. Excluding items, the networking products manufacturer earned 17 cents a share during the second quarter on sales of $88.4 million. Analysts had expected it to earn 14 cents a share on sales of $87.7 million. Looking ahead, it expects third-quarter sales of $98 million to $101 million. Analysts are looking for it to post sales of $94 million. Shares of NetGear traded up $2.34, or 25.7%, to $11.44.

Shares of Opnet Technologies ( OPNT) fell after the company posted in-line first-quarter results but warned that second-quarter results would not meet expectations. The management software company earned 10 cents a share during the first quarter on sales of $16.8 million, matching analysts' estimates. Looking forward, it expects to earn 7 cents to 9 cents a share on sales of $16 million to $16.5 million. Analysts are looking for it to earn 11 cents a share on sales of $17.2 million. Shares of Opnet Technologies traded down $2.14, or 18.6%, to $9.34.

Other technology volume leaders included Intel ( INTC), up 14 cents to $24.38; Microsoft ( MSFT), up 1 cent to $28.49; Cisco ( CSCO), up 12 cents to $20.92; Lucent ( LU), down 6 cents to $3.05; and JDS Uniphase ( JDSU), up 1 cent to $3.45.