Apple’s vice president of mobile advertising Andy Miller has left the company to join Highland Capital Partners as a general partner, AllThingsD reported on Wednesday. Highland Capital Partners bills itself as a “venture capital firm focused on building companies in the communications, consumer, digital media, healthcare and information technology markets,” and says it has invested in over 225 seed, early and growth stage companies since 1988. 100 of those companies have gone public or were acquired by other firms. Miller sold his own mobile advertising firm, Quattro Wireless, to Apple for $275 million in 2010. Apple eventually stopped using Quattro’s technology and instead deployed its own iAd mobile advertising platform across its mobile devices including the iPad, iPhone and iPod touch. AllThingsD said Apple told its staff of Miller’s departure on Wednesday and that the firm will now begin to look for a replacement.