In 1988, Kasem left "American Top 40" because of a contract dispute with ABC Radio Network. He signed a five-year, $15 million contract with Westwood One and started "Casey's Top 40", which used a different chart, the Radio & Records Contemporary (CHR)/Pop radio airplay chart (also employed contemporaneously by "Rick Dees Weekly Top 40"). He also hosted two shorter versions of the show, "Casey's Hot 20" and "Casey's Countdown." During the late 1990s, Kasem hosted the Radio Hall of Fame induction ceremony.