The jury at the International Ballet Competition here came up with two surprises yesterday: They announced the winners a day early, and gave out more medals than they supposed to.

Instead of the 12 medals originally planned, the jurors announce 19. And neither of the two golds scheduled to go to women was awarded, at all.

A spokesman said that once the decisions were made, organizers feared the results would "get out anyway," and thus had moved up the announcement of the winners by a day. As for the variations in the number of medals, the spokesman said they were awarded strictly by the amount of points each contestant had chalked up.

"The standards here were very high," said Thalia Mara, leading figure in ballet in Mississippi and the motivating force that brought the competition to Jackson.

"The women competitors just were not as strong," she said. "The quality of the men was just fantastic."

Mara added that ballet was returning to an era of the male dancer, and that she was glad to see it happen.

In the 11-day contest among 70 dancers from the U.S. and 15 foreign countries, Lubomir Kafka of Czechoslovakia took the highest award, the men's senior gold medal.

Kafka, 23, was the early favorite, and took the top honors with 71 out of a possible 75 points.

Belgian Koenraad Onzia, 17, won the gold medal in the men's junior division as expected. He is a previous gold-medal winner.

The silver medals in the men's senior division went to David McNaughton, principal dancer of the San Francisco Ballet Company, and Yanis Pikieris of Venezuela. There were five bronze medal winners in the senior men's division.

Californian Julian R. Montaner, now with the Ballet Repertoire Company in New York, won the silver in the men's junior division.

In the Senior women's division Jana Kurova of Czechoslovakia took the silver medal. There were four bronze medalists.

In the junior women's division, all three winnners were American. The two silver medalists were Deirdre Carberry of New York - at 13 the youngest competitor - and Jessica Funt (Onzia's partner) of Wilmington, Del. Gretchen C. Newburger of New Orleans won a bronze.

The three winners for choreography were: Joeffry Caulay of LaScala Ballet, gold; Lynne Taylor of New York, silver; and Lew Christensen, of the San Francisco Ballet, bronze.

Two more performances are yet to come. In the awards performance tonight, medalists will repeat their competition dances and receive cash awards ranging from $7,500 for the gold medalist in the senior division to $500 for bronze medalists.

Tomorrow night, finalists will perform dances they have not done previously in competition. CAPTION: Picture, Lubomir Kafka, right, winner of the senior men's division competition, is congratulated by Robbert Joffrey; AP