MIAMI -- Pat Riley's worst season as head coach of the Miami Heat will be his last.

Riley said Monday he didn't want to be a coach anymore. That was good enough for him to step down as coach of the Heat next season.

"Today I am definitely sure that I don't want to do this anymore," Riley said at a news conference announcing his retirement and subsequent hire of assistant coach Erik Spoelstra as his successor.

Spoelstra has been with the Heat since Riley came to Miami from the New York Knicks in 1995. He began his NBA career as the team's video coordinator before being promoted to assistant coach/advance scout and then assistant coach/director of scouting, a role he has served since 2001. He is the son of Jon Spoelstra, a longtime NBA executive.

Riley will remain with the Heat as the team's president but will relinquish his coaching duties. He left no doubt about it when speaking to the media following Monday's announcement.

"I am officially retired," Riley said.

The 63-year-old coach has been with the Heat since 1995, when he left the Knicks after four seasons as their head coach. He coached the Heat for eight seasons while concurrently serving as team president until 2003, when he stepped down the first time following consecutive losing seasons.

Riley remained with the team in a front-office capacity but returned to the bench Dec. 10, 2005, after Stan Van Gundy announced his resignation to spend more time with his family. Six months later, the Heat defeated the Dallas Mavericks in the NBA Finals to win their first world championship in franchise history.

He took a leave of absence in January 2007 to undergo surgery for an ailing hip and knee and returned to the team a little more than a month later. While the Heat limped through a 15-67 finish last season -- the worst record in the NBA -- Riley missed select games to scout players eligible in the upcoming NBA draft.

Riley, who was named to the Basketball Hall of Fame earlier this year, also coached the Los Angeles Lakers to four NBA titles in his nine seasons with the team from 1981 to 1990.