Channel 4 and Channel 50 yesterday announced that starting Monday, Dec. 31, the independent UHF station will air a weeknight half-hour of news at 7:30 to be produced and staffed by the WRC news operation ...

The innovative newscast is tentatively titled "The 7:30 Headline News." The title would deliberately omit any reference to either station ...

According to WRC vice president and general manager Allan Horlick, the NBC-owned station will produce the show at its Nebraska Avenue studios and microwave it live to WFTY studios in Rockville, which in turn will relay the signals to its D.C. transmission tower at Ninth and Peabody streets NW ...

While WRC pays for the air time, it will have rights to all advertising revenues ...

Both stations stand to benefit from the deal -- believed to be the first such between broadcasters in the United States, although some stations are providing newscasts for local cable systems around the country ...

For WFTY, the deal means not only weekly revenue for the air time, but instant respectability from providing a regular newscast, a good lead-in to its regular 8 p.m. movie and -- best of all -- providing a local newscast for a potential audience that has been caught in traffic during the usual 5 to 7 p.m. local newscast times ...

For NBC-owned WRC, the half-hour offers additional revenue from at least seven minutes of advertising time each night and additional, if understated, exposure of members of its news team (principal anchors Jim Vance and Doreen Gentzler won't participate) ...

The program on WFTY, of course, will be competing against the syndicated "Family Feud" on WRC at 7:30, but the prospect apparently doesn't worry Horlick ...

Andy Ockershausen, GM of WFTY, said yesterday that the deal "gives us a chance to perform a service that's not available anywhere else. It's a marriage made in Heaven; WRC has great talent and great facilities. We could never afford to staff up a news show" ...

The station currently airs "The Avengers" from 7 to 8 but a half-hour show will be introduced at 7 when the newscast begins ...

No one has been chosen for the additional WRC newscast but Kris Ostrowski, WRC news director, estimated yesterday that about 15 current staffers -- including three cameramen -- will be assigned to the program ...

International, national and local headlines will be provided by one or two anchors, along with weather, sports and a business report. The program will use tape from NBC sources as well as "some videos" from the earlier WRC newscasts each evening, although, since it's a headline service, in considerably shorter form. According to Horlick, the broadcast will most resemble an early-morning newscast ...

Horlick said yesterday that "we think there's a tremendous appetite for a 7:30 newscast in this market. We will own the program and be completely responsible for selling all commercial announcements" ...

He declined to give details of the arrangement, but other sources suggest it could cost WRC as much as $4,000 to $5,000 a week for the air time on WFTY. The independent station currently averages around a 2 rating in that timeslot. The tough part for WRC will be selling that now small audience to potential advertisers -- although a live newscast in that untried timeslot could be a major selling point ...

Horlick said he expects that "if all goes well, {the deal} could result in a very long-term relationship." It is believed the deal is for a year, with a window for WRC to withdraw after a few months if it proves unsuccessful. But neither Horlick nor Ockershausen would confirm that speculation yesterday ...

The response from rivals was mixed yesterday. WUSA president Hank Yaggi was skeptical ...

"The goodness of this idea eludes me, frankly. Why Allan is directing WRC's energies this way is only something he understands, because I don't" ...

WJLA president Mike Moore was more sanguine. "It sounds like an innovative approach for Channel 50. There's been a lot of activity between broadcasters and cable in this area recently but it's the first I've heard of between broadcasters. It makes sense for WRC as a follow-on to their recent start of a simulcast {of the 5 to 7 weeknight newscasts} on WWDC radio" ...

Tom Herwitz, the boss at Fox's WTTG, said, "These are difficult times and it's always nice to see people who are trying new and exciting things" ...

Horlick said he had approached Ockershausen with the idea several weeks ago and refined details while attending the recent Radio and Television News Directors Association convention in San Jose. Horlick got approval from NBC management last week ...

In another example of NBC-owned stations seeking new ways of presenting the news while keeping an eye on revenues, the NBC-owned station in Denver recently contracted to air its three-hour coverage of election night results on Nov. 6 over a UHF station in the same market, also using its own staff and facilities ...

TV RATINGZZZZ

Following are the top 20 network prime-time shows last week, ranked according to the percentage of the nation's 92.1 milllion TV households that watched, as measured by the A.C. Nielsen Co. A share represents the percentage of actual sets-in-use tuned to a particular program when it aired.

RATINGS...................................SHARE.......NETWORK

1....21.1...Cheers...........................33...........NBC

2....19.5...The Cosby Show...................33...........NBC

3....19.4...A Different World................31...........NBC

4....18.9...America's Funniest Home Videos...30...........ABC

5....18.2...Designing Women..................28...........CBS

6....18.1...Roseanne.........................28...........ABC

7....18.0...America's Funniest People........28...........ABC

8....17.7...Murphy Brown.....................27...........CBS

9....17.2...Unsolved Mysteries...............28...........NBC

10...17.1...The Golden Girls.................31...........NBC

11...16.9...Empty Nest.......................31...........NBC

12...16.4...Matlock..........................26...........NBC

13...15.9...Doogie Howser, M.D...............25...........ABC

14...15.8...Grand............................25...........NBC

15...15.6...Coach............................25...........ABC

16...15.5...Growing Pains....................25...........ABC

17...15.4...Who's the Boss?..................25...........ABC

18...15.2...NFL Bengals-Seahawks.............27...........ABC

.....15.2...In the Heat of the Night.........24...........NBC

20...15.1...The Wonder Years.................25...........ABC

NBC is back solidly in first place after three weeks of the new season but the race between the three big networks is still close ...

For the week ending Oct. 7, NBC averaged a 12.9/22, compared with a 12.5/21 for ABC, a 12.3/21 for CBS and a 6.2/11 for FOX ...

Once again, there was a notable lack of new series in the Top 30. Only ABC's "America's Funniest People," CBS's "The Trials of Rosie O'Neill" (tied for 32nd) and NBC's "Fresh Prince of Bel Air" (37th) made the cut last week ...

ABC's much-ballyhooed "Cop Rock" wound up in a tie for 79th among 93 shows aired last week, while "NBC's "Hull High" and CBS's "Lenny" -- the latter already dispatched to Hiatus -- tied for 81st ...

ABC's two big-ticket Saturday entries, "Twin Peaks" and "China Beach," finished 68th and 78th, respectively ...

In Other News Margaret Pfanstiehl, founder and president of the Metropolitan Washington Ear radio reading service and co-founder, with her husband, Cody, of the Ear's Audio Description Service, last night won a national Emmy for her pioneer work in helping to make TV accessible to blind and low-vision people ...

The award from the National Academy of Television Arts & Sciences was presented at a ceremony in New York ...

The technique involves describing actions, scenes, costumes and body language during pauses in the program dialogue. On TV the voice of the describer is heard via the Second Audio Program channel on stereo receivers. The Pfanstiehls first pioneered and developed audio description for live theater at Arena Stage here in 1981 ...

PBS, which also was honored in last night's ceremony, produces description services for television as a result of Dr. Pfanstiehl's work ...

Channel 32 said yesterday it has a limited supply of 100 tickets available for the public wishing to attend its live, 90-minute mayoral debate Friday night. Tickets, limited to two per person, can be obtained at WHMM studios on the Howard University campus at the corner of Fourth and Bryant streets NW between 9 a.m. and 5 p.m. ...

NBC and the Cable News Network will provide live coverage of today's scheduled landing of the space shuttle Discovery at approximately 9:57 a.m. ...

Meanwhile, let's confirm that "ABC World News Tonight With Peter Jennings" won for the 39th straight week with a 10.2/21, compared with an 8.5/18 for "NBC Nightly News With Tom Brokaw" and an 8.2/17 for "CBS Evening News With Dan Rather" ...

It was the second second-place finish for Tom in the last three weeks ...

Also in the news business, Ike Seamans, Tel Aviv bureau chief for NBC News since June of last year, has been named Moscow bureau chief ...

He replaces Ted Elbert, who will return to New York to become a producer in NBC's "new, expanded investigative unit" ...

Fox Broadcasting has picked up nine additional episodes of "Parker Lewis Can't Lose," which makes Parker the first of the new fall series on Fox to get a full-season order of 22 episodes ...