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Daytona Beach, FL (SportsNetwork.com) - NASCAR announced on Thursday that Richard Buck is replacing John Darby as managing director of the Sprint Cup Series.

Buck currently serves as vice president of racing operations for the International Motor Sports Association (IMSA), a role he will maintain through the Rolex 24 at Daytona, which is scheduled for Jan. 25-26. He has also been serving as the managing director of NASCAR's Touring Series.

"I'm eager and ready to pursue this unique opportunity to serve as the NASCAR Sprint Cup Series managing director," Buck said in a statement. "I appreciate the faith that NASCAR's management team has entrusted in me for this role. As we prepare to launch the 2014 NASCAR Sprint Cup Series season, I'm thrilled to expand my role in the sport of NASCAR, and I look forward to helping the NASCAR Sprint Cup Series competition team continue to produce the best racing in the world."

From 1980-2000, Buck worked as a crew chief, team manager and director of operations with Champ Car teams. He has won five Indianapolis 500s as a crew chief. Prior to joining NASCAR in January 2005, Buck spent five years working with teams in all three NASCAR national series.

"Richard Buck has demonstrated a deep and unique knowledge of motorsports, and his versatility and innovative approach to competition should serve the NASCAR Sprint Cup Series garage extremely well," NASCAR president Mike Helton said. "His wide range of expertise will be of great benefit to our premier series. NASCAR is in the midst of exciting change in the competition area, and Buck will be instrumental in providing us with fresh insights and implementing many of the changes in the years ahead."

Darby, who has been the Sprint Cup Series director since 2002, will remain at NASCAR as managing director of competition. For the past 12 years, Darby has contributed significantly to a number of enhancements for NASCAR, including the introduction of the new Sprint Cup car, the Gen-6, last year.

Buck and NASCAR's two other national series managing directors -- Wayne Auton (Nationwide) and Chad Little (Camping World Truck) -- will report directly to NASCAR vice president of competition Robin Pemberton.