Shares of NetRatings ( NTRT) surged 14.5% Monday after the New York-based Internet research company said it received a proposal from Dutch media conglomerate VNU Group to acquire the outstanding publicly held minority interest in NetRatings for $16 a share in cash. VNU currently owns about 60.5% of NetRatings' stock. NetRatings closed at $14.57 on Friday. Shares were trading up $2.11 around $16.68 Monday.

Powerwave Technologies ( PWAV) tumbled some 18% after the Santa Ana, Calif.-based company, which makes wireless communications network products, lowered its third-quarter revenue guidance. The company said it now expects revenue for the quarter ending Oct. 1 to be in the range of $155 million to $160 million, down from an earlier forecast in the range of $200 million to $210 million.

Analysts polled by Thomson First Call are expecting revenue of $206.2 million. The company cited several reasons for the drop in expected sales, including difficulties in implementing its new ERP system in its European operations, delays in transfer of production from one of its manufacturing locations, and a typically slow third quarter. The company is scheduled to release its quarterly results on Nov. 2. Shares were trading down $1.42 at $6.38.

Brush Engineered Materials ( BW) climbed after the Cleveland-based engineered materials company raised its third-quarter guidance. The company now expects earnings of 32 cents to 36 cents a share on sales of $200 million, up from an earlier forecast of 23 cents to 28 cents a share on sales in the range of $170 million to $180 million. Wall Street is calling for earnings of 28 cents a share on sales of $175.6 million.

For the full year, Brush Engineered expects earnings in the range of $1.20 to $1.28 a share on sales in the range of $725 million to $735 million, up from an earlier estimate of earnings in the range of $1.09 to $1.17 a share and sales in the range of $690 million to $710 million. Analysts are looking for earnings of $1.16 a share on sales of $694.1 million. Shares were trading up $3.31, or 13.8%, to $27.33.

Santander Bancorp ( SBP) gained after the San Juan, Puerto Rico-based bank was upgraded by Sandler O'Neill to buy from hold. Shares were trading up $1.44, or 8.2%, to $19.39.

Celadon Group ( CLDN) gained after the Indianapolis-based trucking company said it bought the truckload business and about 270 tractors and 590 trailers of Erin Truckways for roughly $21 million. Erin Truckways, doing business as Digby Truck Lines, generated about $48 million in gross revenue in 2005.

The company said it offered jobs to about 150 Digby drivers, who will keep their units until seated with newer equipment. Celadon said it will retain about 90 of the newest tractors and about 180 of the newest trailers from the acquisition and dispose of the balance. Shares were trading up 59 cents, or 3.2%, to $19.03 recently.

Digitas ( DTAS) stumbled after the Boston-based marketing company was downgraded by SunTrust Robinson Humphrey to neutral from buy. Shares were slipping 36 cents, or 3.5%, to $10.

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