NBC, its longtime dominance of primetime under challenge from rivals ABC and CBS, yesterday announced mid-season programming changes that add three new series, switch timeslots for three old-timers and cancel four series ...

The revisions will take place next month but exact dates were not revealed in yesterday's announcement ...

Canceled outright will be "Ferris Bueller," "Grand," "Parenthood" and "Working It Out," while "American Dreamer" will head for hiatus. In addition, a summertime sitcom, "Seinfeld," will return to the schedule ...

Only the strong Tuesday lineup will remain intact after January ...

New series joining the lineup will be "Dark Shadows" on Friday, "Blossom" on Monday and a hybrid called "Sunday Best" ...

"Dark Shadows" is the gothic horror series that is rising from its tomb at ABC after a 1971 interment that led to syndication. It stars Ben Cross as the vampire Barnabas Collins, chronicling the mysterious events that begin in Collinsport, Maine, after the arrival of governess Victoria Winters (Joanna Going) and Barney ...

"Blossom" stars Mayim Bialik and Ted Wass in a comedy about "an astute and witty teenage girl coming of age while living with her two older brothers and divorced father" ...

"Sunday Best," which is headed for its own tomb -- the 7 p.m. Sunday slot against CBS's "60 Minutes" -- hasn't been fully defined. Yesterday, a spokesman for NBC Entertainment said he expects a further explanation of the program today. But so far it's called "a topical and comedic magazine show featuring mostly original material, as well as select clips of NBC programs." The original material will apparently include "behind-the-scenes segments of special events and sporting events" carried by NBC as well as highlights from the previous week of NBC programming ...

The revised NBC lineup (new shows and changed timeslots in CAPS):

Monday: "Fresh Prince of Bel-Air" at 8; "BLOSSOM" at 8:30; "NBC Monday Night at the Movies" at 9 ...

Tuesday: "Matlock" at 8; "In the Heat of the Night" at 9; "Law & Order" at 10 ...

Wednesday: "Unsolved Mysteries" at 8; "NIGHT COURT" (moved from Friday) at 9; "SEINFELD," starring comedian Jerry Seinfeld, which had a tryout last summer, at 9:30; and Hunter at 10 ...

Thursday: "The Cosby Show" at 8; "A Different World" at 8:30; "Cheers" at 9; "WINGS," moved from Friday, at 9:30; and "L.A. Law" at 10 ...

Friday: "Quantum Leap" at 8; "DARK SHADOWS" at 9; and "Midnight Caller" at 10 ...

Saturday: "Amen" at 8; "The Fanelli Boys," 8:30; "The Golden Girls," 9; "Empty Nest," 9:30; "Carol & Company," 10; "DEAR JOHN," moving from Wednesday, at 10:30 ...

Sunday: "SUNDAY BEST" at 7; "Real Life With Jane Pauley" at 8; "Expose'" 8:30; "NBC Sunday Night at the Movies" at 9 ...

The network had previously announced that "Real Life" and "Expose'," both from NBC News, would fill the timeslot formerly occupied weekly by "Lifestories," which has become a monthly series ...

NBC, by the way, seems to have found a nice solution for the 10 p.m. Tuesday timeslot. This week, "Law & Order" scored a 14.4 national Nielsen rating and a 26 percent audience share, its best ever ...

That performance left ABC's "thirtysomething" with an 11.9/22 during the same hour. The two-hour "Grammy Legends Show" on CBS averaged a 7.1/12 from 9 to 11 ...

For the night in primetime, NBC led with a 15.8/27, compared with a 14.2/24 for ABC and an 8.4/14 for CBS ...

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

In Other NewsThe Westinghouse Broadcasting Co. (Group W) will close its Washington government affairs office at the end of March as part of a groupwide cost-cutting move ...

Group W -- a subsidiary of Westinghouse Electric -- was one of the first in the industry to establish a government affairs office in the nation's capital more than 20 years ago ...

The closing of the two-person Washington office comes as Group W pares some 40 from its corporate staff. It is expected that further cuts will be made at Group W's five TV and 20 radio stations, currently employing some 2,000 ...

Marcellus Alexander, general manager of Group W's Baltimore outlet, Channel 13, said yesterday that the station -- number one in news and sign-on to sign-off in that market -- announced a limited layoff of eight persons, including six full-time employees, from its staff of about 175 two weeks ago ...

Alexander would not speculate whether the strong WJZ operation was facing further cuts at a time when the entire broadcasting industry is tightening its belt ...

The closing of the Washington office will end a 30-year career at Group W for Washington vice president Gerald E. (Jerry) Udwin ...

Udwin came to Washington 24 years ago to cover Congress and the White House for the Group W news bureau. He later became chief of the bureau. In 1982 he was promoted to the government affairs office and became Washington vice president in 1986 ...

Yesterday, Andrew Schwartzman, executive director of Media Access Project here, expressed disappointment over the Westinghouse decision and the loss of Udwin ...

"For years, Westinghouse has been a class act among broadcasters," said Schwartzman. "This was a company that 30, 40 years ago had trouble with its regulatory status. In the past 20 years or so, Group W's commitment to the idea that broadcasting is a trusteeship has been a model for the whole industry ...

"I also suspect that Westinghouse doesn't understand the value of what Jerry Udwin has done for them in establishing its reputation for community service. They've had extra smooth sailing in dealings with the Federal Communications Commission for years because of Jerry's excellent work" ...

Udwin directed Group W strategy on legislative and regulatory issues affecting its TV and radio stations, syndicated programming division and cable program unit and arranged participation by Presidents Bush and Reagan in the company's national public affairs TV campaigns ...

In a brief announcement this week, Udwin said Group W has asked him to represent the company as a private contractor, either with another firm or by forming his own company to represent Group W and other clients ...

Group W also includes a production arm that produces syndicated programming, satellite communications and is a partner in both Home Team Sports and the Nashville Network cable systems ...

Moving Right AlongFull details will be found in the financial section this morning but we should report that the CBS board of directors yesterday unanimously elected Laurence A. Tisch as chairman of the board, succeeding the late William S. Paley. Tisch will continue as president and chief executive officer of CBS Inc... .

Also, in a move apparently designed to forestall any takeover attempt, CBS Inc. announced an offer to purchase up to 10,526,000 shares of the company's common stock for cash at a price of $190 per share, representing an aggregate share repurchase of $2 billion ...

The Mystery Guest who talked with Ted Koppel on ABC News's "Nightline" Tuesday -- an appearance promoted throughout the night starting on "World News Tonight" -- turned out to be Salman Rushdie, the Indian-born author who has been under sentence of death from the late Ayatollah Khomeini for blaspheming Islam in his novel "The Satanic Verses" ...

"Nightline" had been trying to land the British citizen, who has been in hiding somewhere in England for nearly two years, for about a week and a half, according to spokeswoman Laura Wessner. For security reasons, Scotland Yard had asked producers not to reveal his identity before his appearance in a London studio Tuesday night for the live satellite interview ...

Rushdie's last interview before going into hiding following the threat from fundamentalists in Iran was on "Nightline" Feb. 13, 1989 ...

At the top of Tuesday night's broadcast there was a brief plug for Rushdie's just-published collection of short stories but most of the interview concerned the Persian Gulf crisis and Rushdie's understanding of the Middle East ...

The network -- including "Nightline" offices here -- received many calls from viewers trying to guess the mystery guest (the voice-over promos insisted that "we can't tell you who our guest is ... ") ...

There were votes for Elvis Presley, Frank Sinatra, Saddam Hussein, Yitzhak Shamir -- and Rushdie ...

The interviewed averaged a 6.4/18 in Nielsen's 25-city overnights ...

Each overnight ratings point represents about 470,000 TV homes ...

By comparison, the most recent national weekly ratings average for "Nightline" was a 5.0/15... .

The Koppel interview with Iraqi Foreign Minister Tariq Aziz last Friday night on "Nightline" recorded an overnight 6.6/17 ...