Wall Streets savants dismissed reports Monday that Bill Cosby is mounting another attempt to buy NBC, saying odds of such a deal are about as good as David Letterman moving to ABC to anchor “Nightline.”

A report in Monday’s Wall Street Journal said Cosby was working with investment banker Goldman Sachs & Co. to put together a bid to buy the Peacock web. The alleged principals aren’t talking. This reportedly would be the entertainer’s second attempt to purchase NBC at a time when parent company General Electric has stated the network isn’t on the block.

High-level sources at the network said there had been no discussions in recent months between Cosby or representatives from Goldman Sachs about a possible sale and reiterated that G.E. had no interest in selling the web.

“I don’t think G.E. is going to sell to Cosby or anyone else right now,” said Tom Wolzein, a media analyst with Sanford Bernstein and a former NBC executive. “Why would NBC sell now when it’s hit bottom and is starting the climb back up. Is it possible that Cosby and Goldman Sachs are cooking something up? Sure. But that’s what investment bankers do. When I was at NBC, we saw proposals all the time.”

The consensus among the financial community is that Cosby, whose personal wealth is estimated at $ 300 million, would have an extremely hard time raising the $ 3.5 billion to $ 4 billion that the network would fetch.

The conventional wisdom is that if G.E. were to unload the network, the buyer would be a multinational, like Coca Cola, a studio or a consortium led by someone with a proven operations track record. Paramount, for example, reportedly explored purchasing the network, as did Barry Diller, the former Fox chairman who flirted with the notion of going after NBC before throwing his lot in with the home shopping web QVC.

“Cosby has been superbly successful as a comedian,” said John Tinker, a media analyst for Furman Selz. “But he wouldn’t bring to the job the same set of skills as a Diller.”