President Reagan's presummit primetime interview Thursday night with four network anchors averaged a 16.4 rating and a 24 percent audience share on NBC in Nielsen's 15 major markets ...

On ABC, between 8 and 8:30, the interview averaged a 9.1/14. CBS, which aired the interview at 11:30 p.m., registered a 6.2/16 ...

The cumulative rating of 33.7/54 in the 15 cities suggests Mr. Reagan exceeded by far Mr. Gorbachev's 9.9/15 in the national Nielsens Nov. 30 on a single network -- NBC ...

In Washington, the Thursday interview drew a 17.3/26 on WRC, an 8.5/13 on WJLA and an 8.0/21 on Channel 9 later in the evening ...

The White House, meanwhile, has notified the networks that Mr. Reagan will probably address the nation at 9 p.m. Thursday at the conclusion of the summit meeting with General Secretary Gorbachev ...

Also Thursday, "Simon & Simon" returned to the CBS schedule with a national Nielsen rating of 11.5/18. "Plaza Suite" on ABC could do no better than a 7.9/13 between 9 and 11 p.m. ...

Network Star Wars

A top Soviet official, in Washington to attend the summit, said yesterday that CBS News' claim that the network failed to obtain a one-on-one interview with General Secretary Gorbachev because of tough questions from anchor Dan Rather in Paris two years ago was "simple imagination" ...

Responding to an inquiry from a reporter, Nikolai Shishlin, deputy chief of information for the Central Committee, said he had offered no explanation for the interview turndown when he notified CBS News Moscow bureau chief Wyatt Andrews in late November that the network would not get the interview ...

He rejected claims made in a letter sent to Mr. Gorbachev by CBS News president Howard Stringer on Nov. 18 that "the apparent cause for the rejection was 'CBS News' and Dan Rather's extensive reporting of Afghanistan as well as Mr. Rather's human rights question posed to you {at a Paris press conference} in 1985" ...

Five days later, on Nov. 23, the Soviets announced that NBC with Tom Brokaw had obtained the historic one-on-one interview. It aired Monday, Nov. 30. ABC and Cable News Network had also sought one-on-one talks with the Soviet leader.

Yesterday, Stringer said he stood by his Nov. 18 letter. "Wyatt was informed off-the-record by his own sources that our coverage of Afghanistan and the Paris question was behind it. It was not the first time we've been told that, either. Their wire stories at the time of Dan's stories on Afghanistan called him 'a war criminal.' " Diplomatically avoiding any direct brush with Mr. Shishlin -- CBS News is handling this week's technical services for the Soviet Union -- Stringer said, "No Russian official is going to say why we were turned down, in public" ...

Andrews, on assignment in Washington for the summit, confirmed that Shishlin did not give him an explanation for the turndown, but added that "while I would be very uncomfortable naming my source, I can assure you it was very authoritative. The story is true" ...

He said he was told of the turndown by Shishlin in the course of a conversation that also dealt with several other matters ...

While the question of why the Soviets turned down CBS News for the interview and how CBS News chose to interpret the turndown has not transfixed the general public, it has angered successful bidder NBC News right from the start. Yesterday's recollection by Mr. Shishlin would seem to add to the internetwork sniping ...

NBC (and to a lesser degree, ABC) viewed the Nov. 18 letter from Stringer as a preemptive strike by CBS to diminish the accomplishment of whichever network might eventually get an exclusive interview with the Soviet leader. And indirectly, the letter -- and a separate statement by Rather -- seemed to rivals to be an attempt to cast the CBS anchor in a heroic light not shared by other anchors ...

When, last week, two syndicated columnists used CBS' own explanation for its rejection to suggest NBC and Brokaw were relative pawns in Soviet hands, NBC was once again incensed. Relations between Brokaw and Rather, never warm, have cooled even further. At the White House Thursday, where the two joined ABC's Peter Jennings and CNN's Bernard Shaw to interview President Reagan, Stringer reportedly drew Brokaw aside to assure him that his Nov. 18 letter was not intended to "cast aspersions" on NBC's achievement, or on that of longtime NBC executive Gordon Manning, whose work over 2 1/2 years sealed the coup. ...

This particular scrap arises out of the increasingly intense rivalry among the three major network news organizations and their high-paid anchors as the battle for ratings has become closer. The rivalry is exacerbated when they are in pursuit of a major, exclusive news story. NBC particularly resented CBS' attempt to enhance Rather's image as a tough questioner at Brokaw's expense; CBS is ultrasensitive to any criticisms of Rather, direct or implied, after a year in which the anchor's offcamera behavior has made a couple of headlines ...

Andrews yesterday said the acrimony between NBC and CBS has "recently reached an unnecessary level of meanness" ...

Stringer said he resented NBC's questioning of CBS' veracity, insofar as it comes "from a network that is specializing in public relations these days" ...

On Nov. 18, the same day Stringer wrote Gorbachev, Rather issued a statement that particularly graveled NBC. "The Russians repeatedly made it clear," said Rather, "that to have any chance for a Gorbachev interview, we had to cease our aggressive coverage of the war in Afghanistan and stop asking tough questions about Soviet anti-Semitism. We refused. Neither our conscience nor sense of honor would allow us to do otherwise" ...

While NBC News basked in the subsequent general praise for Brokaw's interview, the echoes of the CBS explanation for its turndown wouldn't die. Last Wednesday, New York Times columnist William Safire characterized Americans "afflicted with Gorby Fever" as believing, among other things, that "sure he's a tough Commie, and yes, he cut out CBS because Dan Rather is too tough on Afghanistan, but Gorby's making real changes; by helping him we help the cause of peace" ...

On Friday, Charles Krauthammer wrote in The Washington Post that "the way the Soviets awarded the interview was a scandal. CBS says it was disqualified because of tough reporting on Afghanistan and tough questions on human rights. ABC likely lost favor because of its mild (and moronic) 'Amerika' series. If so, that means NBC was rewarded for perceived innocuousness" ...

Mr. Shishlin, incidentally, said yesterday that "Amerika," which depicted a Soviet takeover of the United States, did not affect the Soviet decision not to grant ABC an interview. "The general secretary does not pay that much attention" to American television, he said, although he conceded Anatoliy Dobrynin, longtime ambassador to the U.S., now a key policy adviser to Mr. Gorbachev, "remembers 'Amerika.' " ...

ABC News, too, had its doubts about the "apparent cause" Stringer's letter claimed for CBS. Both NBC and ABC wondered in private how a network could be rejected after obtaining the "unprecedented cooperation" CBS bragged of in May when some 50 correspondents spanned the U.S.S.R. in preparation of the three-hour June 24 documentary "The Soviet Union: Seven Days in May," anchored by Rather ...

Friday, ABC anchor Peter Jennings told a reporter he would seek out Soviet officials here this week himself to determine the truth of the CBS News claims ...

Stringer said yesterday that "we are still trying to get our interview with Mr. Gorbachev. In no way was my letter, which I admit I wrote while I was a little angry, intended to take anything away from Gordon Manning's accomplishment." Andrews reiterated yesterday that "our story is accurate, but it was never intended to diminish NBC's success in any way. It was not an attempt by CBS News to suggest that NBC would ever 'take it easy' with the Soviets" ...

Mr. Shishlin revealed yesterday that while all four networks had long had requests in for exclusive, one-on-one interviews ("there was also a proposal for a four-on-one interview. That was a crazy idea"), NBC had been promised an interview by Mr. Gorbachev following the 1985 summit in Geneva. "The general secretary kept his own word," said Shishlin ...

Mr. Shishlin, in making the case for Soviet cooperation with CBS, referred to last week's "CBS Evening News" segments on the Soviet Army, which even included rare looks at SS20 missile installations and which originally were to have included a rare interview by Andrews with Minister of Defense Dmitri Yazov. Mr. Shishlin said that interview is still in the works, for when the summit is concluded, adding that it was postponed only because "the minister had previously agreed to attend an important meeting in Romania last week" ...