ABC Entertainment president Fred Silverman looked out his office window in Manhattan yesterday and into the CBS executive suite across the street. There he saw his old pal Robert A. Daly waving his arms and dancing for joy.

Daly had just been named president of CBS Entertainment. He'd become the Fred Silverman of CBS.

"He jumped up on the ledge and made the V for Victory sign," said Silverman a little later. "He's a very close personal friend and he'll make one helluva competitor."

Silverman could afford to be magnanimous since the sweeping overhaul announced by CBS yesterday seemed clearly modeled after the structure at ABC. It includes dividing the network into "entertainment" and administration halves and making CBS Sports an autonomous unit, the way ABC Sports is.

"Hopefully," Silverman said, "it won't work as well."

Bounced out of his position as president of the CBS Television Network and put in charge of the new sports division was Robert J. Wussler, who took over CBS in April 1976 with the lofty proclamation, "We are No. 1 and we'll remain No. 1."

A few months later they were No. 2 and they remained No. 2. Until this season. Now they're No. 3. CBS has yet to "win" even a single ratings week since the current season begin. So everybody knew something was going to happen.

The restructuring and several key personnel shifts at CBS are clearly reactions to the success that CBS alumnus Silverman has had with ABC in the past two seasons. For two decades CBS was the ratings leader.

Asked if the reorganization was related to the network's ratings woes, a CBS spokesman said, "It would be silly to deny that." But he also pointed out that the network television business has become "too big" for any one executive to handle by himself.

The new president of the network is James H. Rosenfield, formerly in charge of national ad sales for TV. The new president of the CBS Broadcast Group, and the man to whom both Daly and Rosenfield will report, is Eugene F. Jankowski, who started with CBS as a radio account executive in 1961.

Meanwhile, John A. Schneider, who was the Broadcast Group president, has been kicked upstairs to become a senior vice president of CBS Inc. Among his duties there, the network said, will be to "represent CBS in government, industry and international communications matters."

But one industry insider said that Schneider is in effect being shoved aside to make way for the rise of Jankowski, a protege of new CBS Inc.

President John D. Backe.All the changes were announced by Backe and CBS board chairman William S. Paley. Backe's statement called them "evolutionary steps" that will "produce better, and better service to the public both currently and in the future."

What he really hopes, of course, is that they will pull CBS out of the La Brea Tar Pits and move it back toward the pinnacle from which it ruled television for 20 years.

Wussler's demise was attributed by broadcast sources to a number of recent public remarks that proved embarrassing. Wussler chided ratings leader ABC for its "comic-book" programming, apparently forgetting that CBS itself had such shows as "Spider-Man" and "The Incredible Hulk" on the air or on the way.

More recently Wussler declared that even a network ranked No. 3 could still make money. That may be true but it didn't sit well with CBS affiliates who didn't like the idea of settling for last place. Said one insider: "Bobby played it all wrong."