Her departure will end a five and a half year term at Microsoft for Hertel, who joined in September 2002 as regional marketing director, Asia Pacific, Greater China and Japan.
A replacement, who has yet to be announced, is expected to be posted at a more senior level within the company.
Hertel and other Microsoft representatives were unavailable as Media went to press.
Separately, Microsoft's former regional sales director Jonathan Baron has ended a nine-year term at the company to join contextual video advertising firm Vibrant Media as VP of international sales.
Baron moved from Hong Kong to London in October 2006 to take on the role as group sales manager for Microsoft Digital Advertising Solutions.
Meanwhile, the search continues for a replacement for Grant Watts, the former managing director of Microsoft Southeast Asia, who left to join DMS in January.
