The White House and NBC News completed plans Friday that will permit anchor Tom Brokaw to interview President Reagan live at 4:35 p.m. Sunday, Jan. 26, shortly before the start of Super Bowl XX on the network . . .

With an expected audience of 120 million waiting for the kickoff, plans call for Brokaw to spend five to seven minutes with the president. The wide-ranging interview could include a discussion of the role of sports in our culture, the national mood and the phenomenon of such a vast audience watching a single event simultaneously. The president is expected to wish good luck to both contending teams . . .

A source close to the negotiations yesterday would not comment on reports that the live interview might rule out a televised postgame call by the president to the winning locker room. He said that no such postgame call was specifically scheduled during the Friday talks, however . . .

Instead, there seems to be a chance that Mr. Reagan will make a private call sometime Sunday evening to the winning coach . . .

Meanwhile, as the annual January network press tour got under way here over the weekend under weeping skies . . . "Today" show executive producer Steve Friedman revealed that coanchor Jane Pauley hopes to remain on the air through the elaborate July 4 broadcast planned to celebrate the Statue of Liberty restoration . . .

Pauley, the wife of cartoonist Garry Trudeau, canceled plans to meet with TV writers here this weekend with publication of the news that she is expecting a third child later this year . . . In December 1983, she gave birth to twins, Rachel and Richard . . .

Meanwhile, NBC News President Lawrence Grossman yesterday announced that "American Almanac" will join the regular weekly primetime schedule March 4 in the 10 p.m. Tuesday slot currently occupied by "Remington Steele" . . . (Rumors have Remington moving to Sunday night at 10) . . .

Thirty-five hours of "Almanac" have been set by the network, guaranteeing it a full run through 1986. As the year goes by, NBC News will use the "Almanac" time slot once a month to air a series of documentaries . . .

Grossman also revealed that as "NBC Nightly News" anchor, Brokaw will travel to Argentina for nine days later this month and will be in the Philippines for the February presidential elections . . .

On Sunday, March 16, in the 7 p.m. time slot, NBC News and the Entertainment division will air "Talk Back to NBC" . . .

Top executives of the network, including chairman Grant Tinker, Entertainment president Brandon Tartikoff and Grossman will be linked via satellite with studio audiences in some six NBC affiliates around the country for a live Q&A . . . Wait, There's More

Saturday, the "Today" show's Friedman had to carry his 45-minute press conference all by his lonesome. Not only had Pauley begged off, but coanchor Bryant Gumbel, who happened to be in town to tape a two-part interview with Lionel Richie, couldn't get back from Bel Aire in time for the press conference . . .

As a result, it was left to the modest Friedman to gloss over the "Today" show's recent remarkable resurgence . . .

The program ended 1985 by whipping longtime leader "Good Morning America" in the final week with a 5.1 Nielsen rating and a 24 percent audience share, far ahead of GMA's 4.2/20 and "CBS Morning News' " 3.0/15 . . .

That was the fourth win in the past five weeks for "Today" and enabled the NBC show to tie GMA for the fourth quarter (Oct.-Dec.) with identical 5.0/23 figures, while CBS came up with a 3.1/14 . . . the first time "Today" had ranked even with GMA since the fourth quarter of 1980 . . .

Friedman, reluctantly discussing CBS' problems in the early morning race, said that CBS could write a book on "how to destroy a program," based on its experiences over the past three years . . .

Referring to the parade of anchors on "CBS Morning News" in the past few years, he ventured that "strange faces do not make early morning winners" and suggested that GMA and host David Hartman "are still doing a 1978 show" . . .

Friedman noted that CBS is taking its show to Miami later this year, in an apparent attempt to match the "Today" itinerary, which now includes New Orleans for the Super Bowl, Brazil and Argentina for a week in February, a week's cruise in May from Charleston, S.C., to Miami and the live coverage from the Statue of Liberty on July 4 . . .

As for GMA, "they do have to do something" to attract the attention of new viewers . . .

In the past three years, "Today's" yearly ratings have risen from 4.0 to 4.5 and now to 5.0, while GMA has remained stable over the same period at 5.0 and CBS has risen slightly . . .

As for "CBS Morning News," Friedman says it will be a "long arduous process" to get back into the early morning race. "They'll have to do it the Smith Varney way" . . .

And in case you've wondered, NBC research says the average early morning network viewer watches for 37 minutes . . . In Other News

Publisher Rupert Murdoch told independent television executives yesterday that his recently acquired studio is "deeply involved" in producing new shows to be offered by a fourth network . . . and that arrangements should be ready within 60 days . . .

Murdoch bought 20th Century-Fox studios and six Metromedia television stations, including Channel 5 in Washington . . .

"We at Fox at the moment are deeply involved in working to put shape and form on original programs," Murdoch told about 1,000 members of the Association of Independent Television Stations . . .

"These will be shows with no outer limits. The only rules that we will enforce on these programs is they must have taste, they must be engaging, they must be entertaining and they must be original" . . .

The new network plans to compete with the three established networks by selling first-run, primetime shows to independent stations.

It probably will offer situation comedies, one-hour dramas, television movies or "maybe some form not yet seen," Murdoch said.

The shows would be produced at 20th Century-Fox, Murdoch said, but "we're looking at Fox studios as only one source of material.

"Surely our industry is now capable of marshaling the necessary resources to be much more ambitious . . .

"It appears to me, as a newcomer, that our success is due even more to diversity than to quality," he said. "If we are to meet our obligations of added diversity of choice, doing it with old programs is not enough in itself" . . .