CBS News yesterday named Erik Sorenson as executive producer of "CBS Evening News With Dan Rather."

He replaces Tom Bettag, who since 1986 held what has become one of the toughest jobs in network news. Sorenson, 35, has been executive producer of "CBS This Morning" since October 1989, so he is not unfamiliar with third place, which is where "Evening News" has been for the past four weeks, or since the Persian Gulf War broke out ...

The shake-up at "CBS Evening News" didn't end with Bettag. CBS News president Eric Ober also announced that Susan Zirinsky has been named senior broadcast producer on the program. She replaces Bill Crawford, who will probably be reassigned within the division after he takes some time off, according to a CBS News spokesman ...

Ted Savaglio, senior producer of "CBS This Morning" was named interim replacement for Sorenson (who incidentally produced both the morning and evening broadcasts yesterday, for the first and probably last time) ...

Bettag, 47, reportedly has been aware for several weeks that he would be replaced. He had been on the job nearly five years -- a lifetime by network news standards; the show was experiencing another of its periodic ratings slumps; and his relationship with Ober, who replaced David Burke last August, had never been really close ...

Ten days ago, Ober told the network affiliates meeting in Washington that he shared their unhappiness over "Evening News's" faltering start when the war broke out on Jan. 16 and promised some changes ...

The mishaps encountered by Rather in the first 24 hours or so of the war coverage -- a loss of phone lines from Baghdad, lack of satellite accessibility from Tel Aviv -- were no fault of Bettag's but the timing couldn't have been worse, with news-hungry America watching. Recent articles in Advertising Age and the Wall Street Journal citing internal unhappiness over the broadcast, some of it targeting Rather, added to the staff tension ...

Ober, who took over just as the gulf crisis broke out, has been unable to make some long-range changes he has planned for "Evening News," of course, as the news from the Middle East dominates each newscast. Ober, for example, wants to increase coverage of the domestic economic crisis and find an effective way of showing how it affects ordinary citizens but has run into some resistance among "Evening News" staffers, including Bettag, who honors the traditional CBS News "hard news" approach ...

Oddly enough, the appointment of Sorenson may help Rather keep his job. Both Sorenson, schooled in the Los Angeles TV market, and Ober (who once hired Sorenson at CBS-owned WBBM in Chicago) will probably open up the broadcast as much as possible, when possible, perhaps in time to quiet charges by many affiliates that "Evening News" has become "dowdy" and lacks energy ...

Zirinsky arrived in Dhahran, Saudi Arabia, just this past weekend as senior producer of CBS operations and is expected to remain in Saudi Arabia in that job for the next several weeks. Zirinsky, you may recall, was the model for the character played by Holly Hunter in the movie "Broadcast News" a few years back. Her husband, Joe Peyronnin, is vice president and assistant to Ober at CBS News in New York ...

In the memo sent to CBS staffers by Ober announcing the changes -- which moved very early yesterday morning after a night-long series of meetings -- he called Sorenson and Zirinsky "an elite team with a wide range of journalistic experience, talent and creativity. I look forward to their leadership in the years ahead as they and Dan Rather, who led the 'CBS Evening News' through the 1980s, lead a new CBS News flagship broadcast in the 1990s" ...

He said of Bettag: "From Tiananmen Square to Red Square, and from Panama to Iraq where he helped CBS News obtain the first American interview with Saddam Hussein after he invaded Kuwait, Tom Bettag has had more journalistic achievements in recent years than most people get in a lifetime. Tom is a man of great class and an asset to our profession" ...

Bettag yesterday was philosophical about the change. He recalled that then-CBS News president Van Gordon Sauter told him in May 1986, when he took charge of the first-place news program, "The good news is that I have the job. The bad news is that we're pretty sure we're going to fall into third place pretty soon" ...

Sauter was right. By June 1987, "Evening News" had slumped to its lowest rating in 22 years and ABC News began to compete with CBS for second place. "Evening News" made a recovery in September 1987 when the Nielsen switch to "peoplemeters" overnight plunged "Nightly News" from first to third. CBS and ABC then fought it out for first until the fall of 1989, when ABC moved permanently to its current dominance of the news race, with CBS and NBC fighting each week over second ...

"I've had a wonderful run," Bettag said yesterday. "Five years in this job is more than you can expect. I've watched five different News presidents come and go since 1986" (when he replaced Lane Venardos in the job) ...

"The only unfortunate thing about this," he said, "is that I'm leaving the biggest story of my lifetime, with half a million of our kids at risk over there in the Middle East and our own correspondents on a long line, working their hearts out. And of course there're our own missing correspondents" ...

Bettag, who once taught at the Columbia School of Journalism, said he plans to take a good long while off before deciding what to do next. His current four-year contract with CBS News, reportedly signed last year at some $330,000 per, allows him to seek a job outside after May ...

"In May maybe I can look at things on the outside and find whatever place I can to be most effective. I'll talk to Eric about it" ...

A Rather loyalist, Bettag said yesterday that "Dan has been realistic about the change. Executive producers aren't forever, and his job right now is to worry about the war" ...

In a statement, Rather called Bettag "the best broadcast news producer of his generation and one of the greatest ever. The record proves it... . Tom's success is all the more remarkable because he achieved it with modesty and decency, staying true to his principles, to his friends and to himself" ...

Meanwhile, CBS News yesterday notified affiliates that the expanded, one-hour "Evening News" -- the second half of which has not been carried here by WUSA on a regular basis -- would return to a half-hour format starting tonight. Only 30 percent of the network's 200-plus affiliates were clearing the full hour in the most recent count ...

Bad Day at Black RockIt was no surprise to Wall Street, when CBS Inc. yesterday posted a large fourth-quarter loss and said weak advertising demand, coupled with its unprofitable contract to telecast major league baseball depressed 1990 earnings by 63 percent ...

The broadcasting giant also slashed its regular quarterly dividend to 25 cents a share from $1.10, partly because it will no longer earn interest on the $2 billion it recently spent buying back 44 percent of its stock ...

CBS Inc. chairman Laurence A. Tisch also offered a grim forecast for 1991, noting that the recession, costs of covering the Persian Gulf War and the reluctance of advertisers to buy time in war-news shows will depress the company's overall earnings and probably produced an operating loss at the CBS Television Network ...

CBS agreed to pay $1.06 billion for the rights to telecast a limited number of regular season baseball games, the All Star Game, the playoffs and the World Series for four years ...

But sports advertising demand was weaker than CBS expected. In addition, the World Series and one of the league championships ended in just four games, depriving CBS of the revenue that would have come from carrying up to three more games in each series...

But Tisch said that even excluding the sports losses, the CBS network lost an unspecified amount in the fourth quarter. He made no similar estimate for the full year but media analysts estimate it operated at a loss, in contrast to profits at the NBC and ABC networks ...

CBS said it lost $156 million or $6.06 a share in the three months that ended Dec. 31, compared with a profit of $59.5 million, or $2.31 a share, a year earlier. Revenue rose 6.2 percent to $919.7 million in the latest quarter from $865.8 million a year earlier ...

CBS stock rose 25 cents a share to $167.50 yesterday on the New York Stock Exchange but Paine Webber media analyst Alan Gottesman told the Associated Press "this stock is not selling on the basis of how's business; it's trading on whether somebody is going to take it over" ...

In Other NewsABC won the ratingzzz race Tuesday night as that "pivotal" episode of "thirtysomething" attracted 17 millionsomething viewers, helping the network to a 14.9 national Nielsen average and a 24 percent audience share for the evening ...

"thirtysomething" earned a 13.2/23, a season high for the show and well above its season-to-date average of 10.2/18. Meanwhile, next Tuesday, there will be a funeral for poor Gary, and Nancy, who got a clean bill of health, will face two more chemotherapy treatments ...

NBC averaged a 14.5/23 as "Matlock" and "In the Heat of the Night" both recorded 15.8/24's ...

CBS did an 11.9/19. The movie "Not of This World" finished not of the top 20, averaging a 10.5/17 ...

Each ratingzzz point represents 931,000 TV households ...

FOX is bringing back its "Fox Night at the Movies" on Monday nights for a 10-week run, starting April 22. Included in the package will be the broadcast premieres of "Die Hard," "Wall Street" and "Alien Nation" and original titles like "Robin Hood" with Patrick Bergin and "Omen IV -- The Awakening" ...

NBC is bringing back "Shannon's Deal," which a lot of people liked last year. But details are sketchy beyond the fact it will return with a two-hour episode on Sunday, March 17 ...

No timeslot, no date has been set for the series run, however ...

And ABC Entertainment is bringing back Glenn Gordon Caron, creator of "Moonlighting," to develop three series over four years. The first could show up by early next year ...