Arena football, an eight-man variation played indoors and using "the world's biggest pitch-back net," may be coming to Capital Centre in July.

Jim Foster, the game's inventor and a former NFL and USFL executive, said an exhibition would be played in the Centre either July 24 or 31 if a Washington investor would pay for it. In return for financing, the investor would receive the rights to a Washington franchise in a 12-team league Foster hopes to start next May.

"The Capital Centre is ready to go for the game," said Barry Silberman, vice president of arena administration. "We've made the building available, and all we need to hear is a 'yes' from Jim Foster."

Differences between arena football and traditional U.S. football include, most notably, taut nets strung on either side of the goalposts. On missed field goals, the ball is bounced back onto the field and is live. Seven of the eight players are required to stay on the field, 50 yards long, for both offense and defense. No punts or fair catches are allowed, and drop-kicked field goals are worth four points.

JURISPRUDENCE

Former Tennessee quarterback Tony Robinson was indicted by a grand jury in Knoxville on 26 counts of selling cocaine and conspiracy. Identical counts were brought against Robinson's roommate, former fullback Kenneth (B.B.) Cooper. They are accused of selling "in excess of 30 grams" to an undercover police officer between last November and Jan. 8. Judge Ray Lee Jenkins set a Nov. 11 trial date . . .

In New Orleans, a jury of five women and one man was selected for retrial of former Tulane basketball star John Williams on game-fixing charges.

BASEBALL

The National League has called a New York news conference today, apparently to name retiring Yale President A. Bartlett Giamatti as its president, succeeding retiring Chub Feeney . . . Lee MacPhail, the American League's president from 1974-83, is the 1986 winner of The Sporting News' Pioneer Award, to be presented before the National Old Timers Classic June 23 at RFK Stadium . . . California's Wally Joyner leads 1985 league MVP Don Mattingly at first base in early All-Star Game balloting . . . ABC says it was following network policy when it switched from Sunday's Orioles-Yankees game to Red Sox-Brewers and, after the 40-minute rain delay, did not switch back: "The ground rule is that if the rain delay is presumed to be 40 minutes or more, in consideration of our local affiliates scheduled programming , we go to the other game and do not return. We try to provide updates if the original game resumes."

BASKETBALL

Philadelphia 76ers owner Harold Katz says the club is not actively shopping -- "just listening and evaluating" -- Moses Malone for trade before the NBA's June 17 draft. One report in Detroit had the Pistons offering Bill Laimbeer, Kelly Tripucka, Rick Mahorn, Vinnie Johnson and 11th pick in the first round for Malone and first and 21st picks . . .

Maryland's 6-foot-5 Carolin Dehn-Duhr has been ruled eligible for amateur international play on a U.S. team. Meeting in London, the governing FIBA's eligibility committee reversed an earlier decision barring Dehn-Duhr until 1988 under a rule that an athlete must be a citizen for three years. Dehn-Duhr immigrated from West Germany at 5, but did not become a citizen until her 18th birthday last year.

TRACK AND FIELD

The condition of North Carolina State distance runner Kathy Ormsby, permanently paralyzed from the waist down after she jumped from an Indianapolis bridge last week, was upgraded to stable from serious. She is expected to be transferred at midweek to Duke Medical Center in Durham, N.C.

INDOOR SOCCER

The Dallas Sidekicks folded as owner Donald Carter, $5 million in the red for two Major Indoor Soccer League seasons, couldn't find a suitable buyer.