Brad Drewett, a former professional tennis player who later became executive chairman of the ATP (Association of Tennis Professionals) and helped increase prize money at Grand Slam tournaments, died May 3 at his home in Sydney. He was 54.

He had Lou Gehrig’s disease, the ATP, the governing body of men’s tennis, said in a statement.

Mr. Drewett was a top-40 singles and top-20 doubles player before he retired in 1990. He had led the ATP since January 2012 after having been hired in 2006 to lead operations in the Middle East, Asia and the Pacific regions.

Women’s Tennis Association Chairman Stacey Allaster said the prize money increases were “perfect examples of Brad’s brilliant strategic management and another example of how much he cared about our athletes and the sport’s long-term growth.”

Mr. Drewett announced in January that he had amyotrophic lateral sclerosis, or Lou Gehrig’s disease. The disease affects voluntary muscle activity, including speaking, walking, breathing and swallowing. It usually causes progressive disability.

Mr. Drewett’s speech was noticeably slurred when he attended a news conference on the opening day of the Australian Open in January to announce a new sponsor. He had planned to step down once a successor was found.

As a player, he won 181 singles matches and two titles as well as seven doubles titles. In 1975, he captured the Australian Open boys’ singles title and a year later made it to the Australian Open singles quarterfinals in his Grand Slam debut. He reached two Australian Open doubles semifinals and the Wimbledon doubles quarterfinals.

Mr. Drewett also developed and managed a number of successful businesses in tennis and the fitness industry. He also worked as a commentator for two Australian television broadcasters.

Survivors include his wife, Joanne; and four children.

— From news services and staff reports