Small-cap stocks generally underperformed the broad indices Monday, but among the many surging small-cap tech names was

Vonage

(VG) - Get Report

.

Trading volume exploded to push the stock up more than 110% after the voice-over Internet protocol (VoIP) company entered into an

$80 million patent infringement settlement with

Sprint

(S) - Get Report

. Vonage shares jumped $1.29 to $2.44, more than recovering from last month's slide after the Holmdel, N.J., company

lost the related case. Sprint's stock was down 2.7% to $18.49.

United Industrial

( UIC) jumped 6.3% to $80.40 after

Textron

(TXT) - Get Report

agreed to take the maker of aerospace and defense systems out for $81 a share in cash. The roughly $1.1 billion deal should close by year-end. Textron slumped 2.1%.

CIBC World Markets upped

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Novatel Wireless

(NVTL)

to sector outperform, pointing to better-than-expected demand, "particularly in Europe," for new USB product Ovation MC950D. Shares of the San Diego wireless equipment maker climbed 88 cents, or 3.4%, to $26.73.

CalAmp

(CAMP) - Get Report

, an Oxnard, Calif., wireless products maker, soared 17.7% to $4.04 on a Ferris Baker Watts upgrade to buy.

Elsewhere in tech,

China Technology Development

( CTDC) vaulted by one-third after the security software firm swung to a continuing operations profit of $415,000, or 3 cents a share, in the first half of 2007. Last year the Hong Kong concern lost a nickel a share. China Tech first filed the results on Friday, but a press release today spurred shares $2.78 higher to $11.14.

On the flip side,

Edge Petroleum

( EPEX) plummeted 23.3% after the Houston-based oil and gas driller cut its third-quarter production guidance to between 6.1 billion and 6.3 billion cubic feet equivalent, partly blaming the termination of an exploration joint venture in south Texas. Edge previously estimated 6.7 billion to 7.1 billion bcfe. Shares were down $2.97 to $9.77.

That, together with losses at Massachusetts-based

Beacon Roofing Supply

(BECN) - Get Report

helped to pull down the Russell 2000, which surrendered 0.9% to 837.72. Shares of Beacon slid 11.5% to $10.77 after Piper Jaffray downgraded it to market perform from outperform, citing continued broad housing-market concerns.

The S&P SmallCap 600 was shedding about 3.3 points, or 0.7%, to around 439.07.