Dissident shareholders belittled CNet Networks Inc.'s leadership as incompetent and lackadaisical in its latest efforts to steer the slumping technology news and entertainment company in a new direction.

The harsh criticism of CNet's current board and top executives was contained in a 38-page assessment released Tuesday by a mutinous crew of shareholders led by New York investment fund Jana Partners LLC.

Wielding a nearly 15 percent stake in CNet, the disgruntled shareholders have been waging a three-month campaign to overthrow the San Francisco-based company's board.

Tuesday's document provided the most detailed look yet at the potential that Jana sees in CNet's stable of Web sites, which include News.com, TV.com, Mp3.com, MySimon and GameSpot.

By deploying better tools to sell more advertising and highlight CNet's listings in Internet search results, Jana believes it can substantially boost the company's earnings and restore much of the roughly $1 billion in shareholder wealth that has evaporated since December 2005.

"There is no reason to believe that the current leadership, left to its own devices, should be further entrusted to stop the destruction of shareholder value," the Jana-led group said in its assessment.

Besides lambasting CNet's board, the document questioned the Internet savvy of the company's chief executive, Neil Ashe, and chief financial officer, Zander Lurie. The Jana group argued the men's background in investment banking makes them poor choices to lead an online media company.

Without providing specifics, CNet said the Jana group's analysis contains "numerous misstatements" and "is misleading in many respects." Still, the company said it will carefully review Jana's suggestions and "respond in due course."

As part of its turnaround efforts, CNet last week laid off 120 employees, or about 4 percent of its work force.

Although its Web sites rank among the most popular on the Internet, CNet so far hasn't been able to capitalize on the online advertising boom.

U.S. advertisers spent $21.1 billion on Internet ads last year, up 70 percent from $12.5 billion in 2005, according to the Interactive Advertising Bureau.

But CNet's stock has plunged by nearly 50 percent since the end of 2005. CNet shares gained 35 cents, or nearly 5 percent, to finish Tuesday at $7.45.

The Jana group believes its turnaround plan could catapult CNet's stock price beyond $11 next year by improving the company's earnings before interest, taxes, depreciation and amortization, or EBITDA - a key yardstick that investors use to appraise companies.

Jana estimated its plan will generate EBITDA of $183 million in 2009, excluding costs for stock awarded CNet's employees. That's far above the average EBITDA estimate of about $103 million among analysts surveyed by Thomson Financial.

CNet tried to negotiate a truce with Jana last month by offering the dissidents one of the seven seats that they hope to secure on the company's board, according to Tuesday's documents. Jana rejected the offer, calling it "insufficient."