The National Basketball Association received the highest grade ever for racial and gender diversity in men's sports in an annual University of Central Florida study.

The NBA got an overall score of "A-" for the 2006-07 season, up from a "B+" last season, the highest received by a professional men's sport in 14 previous report cards by the university's Institute for Diversity and Ethics in Sport. The NBA received an "A+" for race and a "B" for gender.

Wednesday's report came a week after an academic study from the University of Pennsylvania said that NBA referees showed a racial bias in the way they called fouls. The league, which denounced the Penn study, welcomed the Central Florida findings, headed by the institute's Richard Lapchick.

"Commissioner (David) Stern has from the very beginning wanted us to hire the best possible people, so we have," NBA spokesman Brian McIntyre said in a telephone interview. "It's a diverse world, and it only makes sense to have a diverse workplace."

The NBA received an "A+" for the diversity of its players, league office professionals, and head and assistant coaches. Seventy-nine percent of the players, 34 percent of league professionals, 40 percent of head coaches and 41 percent of assistants are non-whites.

Major League Baseball received a "B" in a similar study issued in March. Report cards for the National Football League, Major League Soccer and the Women's NBA will be released in the coming months.