By Mark Lamport-Stokes

LOS ANGELES (Reuters) - Former UCLA basketball coach John Wooden, one of the most revered figures in U.S. sport, was in "grave" condition in hospital on Thursday, according to multiple media reports.

The 99-year-old Wooden was being treated at UCLA Medical Center, the Los Angeles Times and Los Angeles television station KCAL each reported.

Although his family could not be immediately reached for confirmation, leading officials attending Thursday's Game One of the NBA Finals were aware of Wooden's failing health.

"We discussed it at length, and we decided that we would not declare his obituary now," NBA Commissioner David Stern told reporters.

"He's the winningest coach in our history, four 30-0 seasons, and the ultimate aficionado of our game. We hope he's in peace right now, and we'll wait on events."

Under his charge, Bruins teams registered a record 88-game winning streak from 1971-1974, four perfect 30-0 seasons and strung together 38 consecutive NCAA Tournament games from 1964 to 1974.

Affectionately dubbed the "Wizard of Westwood", he ended his career with a win-loss record of 667-161 after 29 years of college coaching.

Wooden became the first person to enter the Basketball Hall of Fame as a player (1961) and as a coach (1973).

"He established a goal that is unreachable in college sports, obviously," Lakers coach Phil Jackson said before Thursday's Game One.

"And held it to such a standard that we all appreciated his teaching and his mentoring of his college students. His coaching has been an inspiration to all of us coaches."

(Editing by Frank Pingue; To query or comment on this story email sportsfeedback@thomsonreuters.com)