Updated from 12:06 p.m. EDT

Shares of American Power Conversion ( APCC) were among the Nasdaq's losers Friday after the company posted weaker-than-expected second-quarter results and warned that second-half sales would face difficult year-over-year comparisons.

The maker of power-protection systems posted a second-quarter profit of 13 cents a share, down from 17 cents a year ago. Sales climbed to $395.7 million, from $331.5 million a year ago. Analysts polled by Thomson First Call had expected earnings of 19 cents a share on sales of $375.7 million. Looking forward, American Power said that "it is important to recognize that the year-over-year revenue growth rate for the second half of 2003 was 19%," making for "difficult comparisons" during the rest of 2004. Shares traded down $2.35, or 13.5%, to $15.10.

THQ ( THQI) fell after it reported in-line first-quarter earnings results but warned that second-quarter results would fall short of expectations . The video-game maker reported a loss of 10 cents a share in the first quarter on sales of $88.2 million. Analysts had expected a loss of 10 cents a share on sales of $86.6 million. Looking ahead, the company expects a third-quarter loss of 20 cents a share on sales of $82 million.

Analysts were expecting a profit of 6 cents a share on sales of $128.4 million. THQ said the second-quarter shortfall would be made up during the second half of the year, when the company launches several game titles during the holidays. As such, THQ revised its full-year guidance to earnings of $1.10 a share on sales of about $680 million. Analysts were expecting earnings of $1.07 a share on sales of $682.6 million. Shares of THQ traded down $1.35, or 6.6%, to $19.05.

Shares of Pope & Talbot ( POP) rose after the company posted better-than-expected second-quarter earnings and sales. The pulp and wood products company earned 58 cents a share on sales of $193.6 million. Analysts had expected it to earn 25 cents a share on sales of $174.4 million. The second-quarter results were driven by market-price increases in its pulp and lumber products. Shares of Pope & Talbot traded up 71 cents, or 3.8%, to $19.62.

Janus Capital ( JNS) fell after it disclosed that a client intends to withdraw $5 billion from its funds , or about 3.7% of the company's total assets under management. The mutual fund company did not provide the name of the client but did say that the withdrawal would take place by the end of the year. Separately, Janus announced that executive vice president Lars Soderberg resigned from the company, effective July 21. Soderberg had been on leave since April. Janus will pay Soderberg $1.5 million as part of a separation agreement. Shares of Janus Capital traded down 63 cents, or 4.5%, to $13.26.

Shares of Multimedia Games ( MGAM) fell after the company reported weaker-than-expected third-quarter results and warned that fourth-quarter results would fall well below expectations. The casino-game maker earned 32 cents a share during the third quarter on sales of $123.5 million. Analysts had expected earnings of 34 cents a share on sales of $142.3 million. Looking ahead, Multimedia Games expects to earn 37 cents to 42 cents a share during the fourth quarter. Analysts had expected it to earn 43 cents a share. For the full year, the company expects to earn $1.20 to $1.25 a share, below analysts' expectations. Shares of Multimedia Games traded down $5.63, or 22.9%, to $18.91.

NYSE volume leaders included Lucent ( LU), down 6 cents to $3.05; Nortel Networks ( NT), down 7 cents to $3.66; Foot Locker ( FL), up $1.14 to $22.50; Pfizer ( PFE), up 3 cents to $31.96; General Electric ( GE), up 4 cents to $33.25.

Nasdaq volume leaders included Intel ( INTC), up 14 cents to $24.38; Conexant Systems ( CNXT), down 30 cents to $1.59; Microsoft ( MSFT), up 1 cent to $28.49; Cisco ( CSCO), up 12 cents to $20.92; and JDS Uniphase ( JDSU), up 1 cent to $3.45.