The long-sought interview with Soviet leader Mikhail Gorbachev broadcast by NBC News last night sent the world's news media organizations scrambling yesterday for an advance look at the hour-long exclusive.

Although newspapers and wire services obtained embargoed transcripts of the interview by anchor Tom Brokaw in midafternoon, giving them time to digest whatever news was available, CBS News, ABC News and CNN had their first crack as their anchors were sitting down to begin the evening news shows.

CBS and ABC concentrated on the stock market and tumult in Haiti and mentioned NBC's interview only briefly toward the end of their reports.

But rival network executives acknowledged that, no matter how much notice they took of Brokaw's interview, NBC had grabbed the brass ring all of them had been reaching for.

"NBC scored one hell of a coup," said Ed Turner, executive vice president of Cable News Network. A spokesman for ABC's "Nightline," which received NBC's permission to air five to six minutes of the interview last night, said, "It was a real scoop, and we're saying that."

The Gorbachev interview, the result of years of courting by NBC executives, was the first sign that summit fever has begun to grip the international news community.

With the summit between Gorbachev and President Reagan scheduled Tuesday through Thursday of next week, Washington is preparing for an event that will be covered, at whatever level possible, by about 6,000 very competitive journalists.

James Pope, director of the U.S. Information Agency's Foreign Press Center, said yesterday that about one-third of those journalists will represent U.S. television stations while the rest are coming from around the globe, including one from Bangladesh and another from Tanzania.

One source said that ABC asked for credentials for 700 persons but was asked by the White House to pare the requests to 500, which was done. CBS, according to this source, is the only network that will have a hairdresser with a press pass.

Many news organizations, particularly television, will turn to experts to explain what is being said and not said. With six days remaining before Gorbachev arrives here Monday, the networks and other television news organizations have engaged in a virtual bidding war for Soviet experts.

For example, Dmitri Simes, who helped CBS at the last summit but had a rift with the network over its documentary on the Soviet Union earlier this year, has moved to NBC for this summit.

The senior associate at the Carnegie Endowment for International Peace said his contract with NBC involves primarily "special events," which do not include nightly news shows.

ABC has signed Condoleezza Rice, an associate professor of political science at Stanford University, and is seeking other experts, according to an ABC spokesman.

CBS employs sovietologist Jonathan Sanders of Columbia University. It also will field former U.N. ambassador Jeane J. Kirkpatrick to provide occasional observations and "a couple of people who would be on the opposite side of the political spectrum," said Lane Venardos, the network's director of summit coverage.

While the networks are wooing experts, spokesmen for the experts are signalling their availability, especially since news organizations credit the think tank or university that employs them.

American University, for example, sent manila envelopes stamped with this notice: "For Your Summit Stories: Expert List Enclosed."

A conservative group called the Summit Information Center has offered a list of possible experts, including Ray S. Cline, former deputy Central Intelligence Agency director and Lt. Gen. Daniel O. Graham, former director of the Defense Intelligence Agency. The Heritage Foundation and other conservative groups also are touting experts.

On the other side politically is SummitWatch, which provides experts and has scheduled a breakfast Thursday with former SALT negotiator Paul Warnke; Natural Resources Defense Council scientists Thomas Cochran and Robert Norris; and William Arkin, director of the national security program at the Institute for Policy Studies.

A Brookings Institution list brought "quite a few calls," said the think tank's public affairs director, David A. Hamod. Are Brookings people going to be on television for the summit? "One would hope so," he said. "Their contributions are substantive."

The networks are planning specials each night and coverage that dips into the daily schedule whenever a major briefing or news event occurs. There will be Soviet briefings and White House briefings, demonstrations and impromptu news conferences.

"We're not going wall-to-wall," said CNN's Turner, referring to television's term for minute-by-minute coverage. "But it's damn near."