Updated from 12:45 p.m.

Shares of

CommScope

(CTV) - Get Report

were among the worst-performing technology stocks Tuesday after the company warned it would post weaker-than-expected third- and fourth-quarter sales results.

The communications gearmaker now expects third-quarter sales of $307 million to $311 million. Previously, the company said that it would post sales of $300 million to $320 million. Analysts polled by Thomson First Call had been expecting sales of about $315 million. For the fourth quarter, CommScope expects sales to fall 5% to 10% below third-quarter results. Analysts had been expecting sales of $312.3 million. Shares traded down $3.80, or 17.3%, to $18.20.

C-COR

(CCBL)

fell 8.6% after the company lowered its first-quarter sales outlook and said that earnings would come in at the low end of its previous earnings guidance of 2 cents to 5 cents a share. Sales are now expected to be about $62 million, down from its previous guidance of $64 million to $67 million. Analysts had been expecting earnings of 7 cents a share on sales of $66.2 million. The company blamed the shortfall on delays in software sales during the quarter. Shares traded down 74 cents to $7.85.

Shares of

Amkor Technology

(AMKR) - Get Report

fell 1.2% after the company said the

Securities and Exchange Commission

is conducting an informal inquiry into the trading of Amkor's securities. The contract semiconductor assembly company said it believes the inquiry relates to transactions in the company's securities by individuals that may include certain insiders. Amkor has received requests for documents and other relevant material relating to the trading. The company, which believes the inquiry relates to transactions in 2004, said it is cooperating with the SEC. Shares traded down 5 cents to $4.21.

Harmonic

(HLIT) - Get Report

fell 3.1% after the company warned that third-quarter earnings and sales would not meet expectations. The provider of digital communications equipment expects a pro forma loss of 3 cents to 5 cents a share on sales of $50 million to $51 million. Analysts had been expecting a profit of 4 cents a share on sales of $61.3 million. Harmonic said third-quarter sales were impacted by the timing of two customer orders received by one of its divisions. Shares of Harmonic traded down 22 cents to $6.91.

Shares of

Travelzoo

(TZOO) - Get Report

rose 11.4% after the company posted a 240% jump in earnings on a 99% improvement in sales. The Internet travel site earned 12 cents a share during the third quarter on sales of $9.5 million. Shares of Travelzoo, which have gained about 650% so far this year, traded up $6.47 to $63.35.

Other technology volume leaders included

Sirius Satellite Radio

(SIRI) - Get Report

, up 23 cents to $3.75;

Intel

(INTC) - Get Report

, down 33 cents to $20.28;

Microsoft

(MSFT) - Get Report

, down 3 cents to $28.03;

Cisco

(CSCO) - Get Report

, up 18 cents to $19.16;

Applied Materials

(AMAT) - Get Report

, down 13 cents to $16.16;

Oracle

(ORCL) - Get Report

, down 5 cents to $12.15; and

Lucent

(LU)

, down 6 cents to $3.38.