Up 43% - CNet Networks Inc. (CNET) shares rose to a 52-week high Thursday after the company and CBS Corp. said that CBS will buy the online news and information provider for about $1.8 billion in cash. (AP)

Up 24% - Oil and gas income trust Enterra (ENT) surged.... The Calgary, Canada-based company narrowed its first-quarter loss to $1.9 million, or 3 cents a share, from $62.8 million, or $1.12 a share, a year ago. The loss was due primarily to unrealized mark-to-market losses of $6.8 million, the company said.

Up 11% - Shares of Stanley Inc. (SXE), which provides systems integration and professional services for the federal government, climbed Thursday after the company's fiscal fourth-quarter results exceeded Wall Street's expectations. Late Wednesday, Stanley said its March-quarter profit grew 70 percent and revenue grew 49 percent, as the company gained new contracts and picked up business from Techrizon, which it bought in April 2007. Profit and sales both surpassed analyst expectations. (AP)

Up 8% - Prestige Brands Holdings Inc (PBH), a maker of healthcare, personal care and household products, posted quarterly earnings above market estimates, and said it is looking to sell its personal care segment and certain small over-the-counter brands. ... The stock had risen 15 percent so far this year before Thursday's gains. (Reuters)

Up 8% - Shares of Agilent Technologies Inc. (A) surged at market open Thursday after the scientific equipment maker posted better-than-expected fiscal second-quarter results. (AP)