INDIANAPOLIS, AUG. 17 -- Six athletes were disqualified from the 10th Pan American Games after testing positive for drug use, including U.S. hammer throw silver medalist Bill Green, international organizers announced today.

Mario Vazquez Rana, president of the Pan American Sports Organization, said the six athletes will be excluded from competition and stripped of any medals. Other sanctions may come from the international federations of their respective sports.

"It is regrettable that we have to fulfill this mission today, and we hope there will be no more cases throughout these Games," Vazquez Rana said.

Green, a 1984 Olympian who was born in Laurel, Md., and grew up in Torrance Calif., tested positive for an extraordinary level (more than double the amount permitted by International Olympic Committee rules) of testosterone, a male hormone that in large amounts can produce effects similar to that of anabolic steroids. He could not be reached for comment, but a spokesman for the U.S. Olympic Committee said Green would challenge the finding. Steroids are commonly used by athletes to produce extra strength and weight development.

{Reached at his home by Knight-Ridder Newspapers, Green said, "I really don't have anything to say at this time."}

But Stephen Sobel, USOC vice president, who is serving as U.S. chief of mission, said Green has obtained counsel to fight the decision.

"The athlete has advised the USOC that he wishes to pursue furthur remedies to challenge the testing procedure and results," Sobel said. "Therefore, the USOC does nco believe that it is appropriate to make any further comments."

The other athletes who tested positive were: Orlando Vasquez-Mendose of Nicaragua, a triple bronze medalist in weightlifting, for hydrochlorthiazide, a diuretic. Vasquez-Mendose used the drug to reduce his weight. Pedro Torres of Venezuela, for the steroid nandrolone. He did not win a medal. Elnes Bollings, a basketball player from the Virgin Islands, for phenylpropanolamine, a stimulant. Bernardo Ocando, a pistol shooter from Venezuela, for the relaxant propranolol. Ocando was a double medalist, winning a bronze in air pistol and a silver in the team competition. Shooters sometimes use relaxants in order to perform more consistently. Weightlifter Javier Jimenez of Colombia, for the steroid nandrolone. He did not win a medal.

A number of questions have been raised about drug testing procedures here in the last week. According to some athletes and officials, testing at track and field events suffered from a lack of organization on the first day of competition. Also, there are conflicting statements from officials on whether all medalists have been tested, as the Pan Am governing body requires.

Dr. Eduardo Henrique De Rose, president of the PASO medical commission, which is in charge of testing and which issued the recommendation to disqualify the athletes, said earlier today that not all medal winners have been tested in every sport. But Vazquez Rana has issued conflicting statements as to who has actually been tested, and under what circumstances.

Vazquez Rana denied that there was any potential for mistakes in the testing, and asserted that medalists in every sport had been tested.

Vazquez Rana said there were two or three more instances of potential positive results that were being studied by the Pan Am medical commission.

Green had already departed the Games when the findings were announced. According to International Amateur Athletic Federation rules, he is subject to a lifetime ban from track and field, but can appeal after 18 months. That, however, would keep him out of the 1988 Olympics in Seoul if the finding here is not reversed.

An athlete is tested twice to ensure a correct result. However, Vazquez Rana could not explain the statements by De Rose earlier in the day that not all medalists were being tested.

Also, earlier this week De Rose said that on Aug. 9, the first day of track competition, the testing was plagued by problems ranging from lack of escorts and lack of fluids to inadequate facilities. Green was apparently tested on the second day, when testing reportedly ran smoothly.

According to De Rose, a total of 600 tests have been taken with 400 results back, and a total of 1,000 will be tested for the entire Games. In track and field, and weightlifting, the three medalists plus a random athlete are tested. But he said in swimming and shooting, for instance, not all of the medalists have been tested, because of the federations' insistence that testing be random rather than medal-oriented. Also, he said the number of medalists and expenses would prevent testing everyone.

This is the second time drug testing has become an issue at the Games. In 1983 in Caracas, Venezuela, 17 athletes from nine nations, including 11 medalists from six nations tested positive, primarily for steroid use. Two of them were U.S. entrants. Also, a group of 12 U.S. athletes left those Games without competing for personal reasons.

Where medals were stripped from competitors, Vazquez Rana said they would go to the next highest finisher.