Biggest Losers (RVSN,ROC,PAG,UAUA,ASTI)

RADVISION LTD. (USA) (NASDAQ: RVSN)  plummeted 31% to $6.16 on huge volume of 4.20 million shares and fell 37 percent earlier for the biggest intraday retreat since March 2000. The Israeli maker of video- conferencing systems dropped after Cisco Systems Inc. (CSCO US) agreed to buy rival Tandberg ASA. (TAA NO)

Rockwood Holdings, Inc. (NYSE: ROC) fell 21% to $16.89 on unusual volume of 3.35 million shares after Credit Suisse downgrades from Outperform to Neutral. Price target $22.

Penske Automotive Group, Inc. (NYSE: PAG)  decreased $2.92 or 15.22% to $16.26 on huge volume of 3.34 million shares after the publicly held chain of more than 300 dealerships said it has terminated its discussions with General Motors Co. to acquire the Saturn brand, citing concerns about the future supply of vehicles beyond the supply period it had negotiated with GM.

UAL Corporation (NASDAQ: UAUA)  corrected 15% to $7.90 on very unusual volume of 12.96 million  shares after the company said it will sell at least 19 million shares of common stock and $175 million in convertible debt, joining an industrywide push to add cash before the slow winter travel season.

Ascent Solar Technologies, Inc. (NASDAQ: ASTI) plunged 15.37% to $6.38 on very unusual volume of 1.67 million shares after priced its previously announced public offering. Ascent Solar is offering 4.6 million shares of its common stock at $6.50 per share to the public. Net proceeds from the offering are expected to be used for expansion of Ascent Solar's rated production capacity and for general corporate purposes.