Brian Gottfried and Raul Ramirez, having lost the intangible rapport that made them one of the most successful doubles teams in tennis for four years, have split up as partners, at least for the forseeable future.

Their decision, reached mutually and amicably at the start of the French Open two weeks ago, could lead to an interesting round of "musical partners" among some of the game's top doubles players.

Ramirez, for instance, already has agreed to play Wimbledon and four U.S. tournaments this summer, including the Washington Star International, with Fred McNair IV of Chevy Chase, Md.

McNair's regular partner of the past 3 1/2 years, Texan Sherwood Stewart, is playing World Team Tennis this summer. Stewart-McNaire were going to play Wimbledon and the U.S. Open together, but when Ramirez became available, McNair telephoned Stewart and told him he would like to play the summer circuit with Ramirez as his regular partner.

Gottfried, 26, of Fort Lauderdale, and Ramirez, 24, of Mexico, agreed to a "trial separation" because both felt a break would do them good.

"We're not nearly the team we were," said Gottfried. "It sounds crazy, but when you're playing doubles all the time and traveling together, it's like a marriage. It's difficult to maintain a certain level and mood.

"But this is definitely a separation rather than a divorce. We made it clear that we're still partners. We're just taking a break. We expect to get back together sometime."

Gottfried and Ramirez were an instant success after being thrown together as a makeshift team in the spring of 1974. They won the Italian Open doubles four straight years (1974-77), the French in 1975 and '77, Wimbledon in 1976, and the World Championship Tennis (WCT) doubles in 1975. They were runners-up to Bob Hewitt and Frew McMillan in last year's U.S. Open.

"We won a lot right from the beginning, but we've gotten a little stale.We couldn't seem to get ourselves up for doubles anymore. We weren't eager, enjoying it, getting excited like we used to. We weren't communicating on the court," Ramirez said.

"We both stated thinking about it. There's no sense playing together, hoping it will get better, if it isn't happening. We both decided a break would be the best thing. Maybe we'll come back in 1979 and win everything . . . but little things were building up, and we wanted to stop before it affected our friendship."

Gottfried and Ramirez won only one tournament together this year: the U.S. Indoors at Memphis. They had some unaccustomed bad losses, to the "pickup" team of Ilie Nastase and Mike Fishbach in Philadelphia, and to Gene Mayer and Pat DuPre in Washington. They lost to Jan Kodes and Tomaz Smid in the semifinals of the Italian, snapping their five-year, 23-match winning streak in Rome, and to eventual champions Mayer and Hank Pfister in the semifinals of the French last week.

Gottfried has agreed to play a couple of tournaments this summer with Pfister, but otherwise his doubles plans remain unsettled. "I'd like to try to play with an American, for Davis Cup reasons," he said.

He ruled out playing with McNair because they both play the right court, but McNair pointed out that before turning pro and teaming with Stewart, he played the left court most of his life.

"I've won pro tournaments in the left court with Marty Riessen and Wojtek Fibak playing the right. I've actually had more experience in the left court, and prefer returning serve from that side." McNair said.

"When you think of a left-court player, you think of one who has a consistent return of serve and is accustomed to playing big points because, generally speaking, the guy in the 'ad' (left) court is responsible for initiating the action on that side.

"Maybe the rest of my game and personality is suited to the right court - I'm pretty flamboyant and like to gamble - but I'm more comfortable returning serve from the left. I tink Gottfried and I would be a viable Davis Cup doubles team," said McNair.

The top-ranked U.S. team of Stan Smith and Bob Lutz will not be available for the American Zone finals against Chile in Santiago, Sept. 17-19, because Smith's wife is expecting their first child that week.

McNair has made nearly $40,000 in prize money in doubles this year, playing mostly with Stewart the first four months.

He won a tournament in Baltimore with McMillan and has played twice with Ramirez in the left court, winning a WCT tournament in Rotterdamk and reaching the semifinals at Monte Carlo. McNair and Arthur Ashe lost in the first round in Rome, to Fishback and Bernie Mitton, and in the quarterfinals in Paris, to Ramirez and Gottfried.

McNair has played singles in only two tournaments this year, losing to Englishman John Lloyd in the first round in Rotterdam and again in Rome. His computer ranking of 182 is too low to allow him direct entry into most tournaments without qualifying, and he is frequently unable to play qualifying events because he is still involved in the doubles somewhere else.

"Right now, I'm sort of in a mental dilemma as to what I should do with my tennis career," McNair said. "Should I be content with concentrating on doubles? And if so should I make a change in partners to someone I can play with year-round? Or should I try to work on my singles and get my ranking back up?"

McNair and Stewart were ranked No. 1 in the U.S. in doubles last year, but with Stewart having signed a three-year contract with WTT, they are unable to play together four months a year.

"I might need a permanent change of partner to accomplish my goals - to make the Grand Prix Masters in doubles and be part of the best team in the world," McNair said.