Miami, FL -- (Sports Network) - The Miami Heat made a coaching change on Monday, as Pat Riley stepped down and was replaced by assistant Erik Spoelstra.

Riley, elected to the Basketball Hall of Fame earlier this year, will remain the team's president.

"I'm officially retired," Riley said Monday at a news conference. "I do want to continue in basketball. Today, I think the move we are going to make is in the best interests of the Heat."

Spoelstra has spent 13 seasons with the Heat, the first two as a video coordinator under Riley. He ascended to an assistant coach in 1997 and has also been the franchise's director of scouting for the past seven seasons.

"In the years that I've worked here for coach Riley, I've learned about the NBA, I've learned how to coach and I've developed my skills as a leader," Spoelstra said Monday.

Riley's exit comes following a tremendous on-court struggle for his team. Just two years removed from coaching a team led by Dwyane Wade and Shaquille O'Neal to the NBA championship, the Heat floundered to an NBA worst 15-67 record this season.

"I understand the challenge we have here," added Spoelstra, who, at age 37, will be the youngest coach in the league.

Spoelstra has never been a head coach on any level, although he has coached Miami's summer league team.

The 63-year-old Riley has been with the Heat since 1995, when he left the New York Knicks after four seasons as their head coach. He coached the Heat for eight seasons until stepping down in 2003.

Riley remained with the team in a front-office capacity but returned to the bench in 2005 after then-coach Stan Van Gundy announced his resignation just 21 games into the campaign.

Six months later, the Heat upended the Dallas Mavericks to win their first and only NBA championship in franchise history.

This past season, Riley took a leave of absence in January 2007 to undergo surgery for hip and knee problems before returning to the team a little more than a month later.

Riley also coached the Los Angeles Lakers to four NBA titles during a nine- year run from 1981-82 through 1989-90.

In 11 seasons as head coach of the Heat, Riley posted a record of 454-395. Overall, he has a mark of 1,210-694. Only Lenny Wilkens and Don Nelson have more NBA victories.