California-based biotech company Amgen will continue its title sponsorship of the Tour of California bicycle race for two more years. Two independent sources with knowledge of the race confirmed the deal, which is believed to be valued in the mid-seven-figure range. Amgen has held the title sponsorship of the eight-day race since it began in '06. The event, owned and operated by AEG Sports, has grown into the largest professional bicycle race in the U.S. and each year attracts riders and teams that compete in the top events in Europe. Sources valued the race’s operating cost in the $12M range. Amgen's other cycling deals include sponsoring a non-profit amateur cycling club in California since '01.