Bjorn Borg was designated the "world champion" of men's tennis for 1978 yesterday by the International Tennis Federation, and used the occasion to announce his intention to play the 1979 Colgate Grand Prix.

The "world champion" title is a new honor to be awarded annually by the ITF. It is intended to established an official No. 1 player for each calendar year, eliminating the confusion caused by diverse and often contradictory sets of unofficial rankings.

Borg, 22, was the unanimous choice of the selection panel composed of three former champions: Englishman Fred Perry, Australian Lew Hoad and Californian Don Budge.

Borg -- who won the Wimbledon singles title for a third consecutive year, duplicating a feat last achieved by Perry in 1934-35-36 -- was the obvious choice over the only other serious contender, U.S. Open champ Jimmy Connors.

Borg had a superior record in traditional major events. He was the first man since Rod Laver in 1962 to sweep the Italian and French opens, the two most important European clay-court tournaments, and Wimbledon in the same season. He also had a 10-0 singles record in Davis Cup competition.

Borg beat Connors, 6-2, 6-2, 6-3, in the Wimbledon final on grass and lost to him 6-4, 6-2, 6-2, in the U.S. Open final on cement. In the rematch, Borg was hampered by a blistered thumb on his racket hand.

Those were the arch rivals' only two meetings in regular tournaments during the ranking season, but Borg had a 2-1 record over Connors in four-man "special events."

Borg's record for the entire season was 85-8. Excluding four-man events, he was 72-7. From January through the U.S. Open final in September, he had a 55-match winning streak. In the French final, he beat defending champ Guillermo Vilas, 6-1, 6-1, 6-3.

Connors was 82-7 overall, 76-5 excluding special events. Following the Wimbledon final, he compiled a 32-match winning streak.

John McEnroe won four tournaments and the Colgate Masters play-off in a spectacular surge after Connors beat him in the U.S. Open semifinals, but was not a candidate for No. 1 on the basis of his full-season record of 75-20.

Borg said at a Paris press conference yesterday that his goals for 1979 would be a fourth Wimbledon title and the French-Wimblendon-U.S.-Australian Grand Slam accomplished by only two men: Budge (1938) and Laver (1962 and 1969). He intends to play Davis Cup for Sweden and at least 13 Grand Prix tournaments, starting in Richmond, Jan. 29-Feb. 4

Borg, Connors, McEnroe, Vilas and Vitas Gerulaitis, the top five players of 1978, have not yet signed agreements to play in the $12 million 1979 Grand Prix series, embracing 93 tournaments around the world.

They have objected to new rules for the Grand Prix requiring each player to enter six tournaments designated by the Men's International Professional Tennis Council, including three of $75,000 or less, and limiting the number of "special events" each player can enter during the season.

Players failing to sign have been told they will not be allowed to play any Grand Prix event, including Wimbledon and the U.S. Open, but the signing deadline has been extended to March 5. John McEnroe Sr., a Wall Street lawyer acting on behalf of his son and the other unsigned players, has threatened legal action.

However, Borg said yesterday he intends to sign up for the Grand Prix and Vilas is on the verge of following suit, according to David Gray, general secretary of the ITF and the Pro Council. Their signings would severely undermine the "holdout" of Connors, McEnroe and Gerulaitis for a change in the rules.

Chris Evert was named the women's "world champion" by an ITF panel of three former women champions -- Ann Jones, Margaret Court and Margaret duPont -- in December.