Lauren Kapp, one of Arianna Huffington's key advisors at the Huffington Post Media Group, is leaving the company, effective August 1.
She is leaving for personal reasons, an AOL spokeswoman confirmed.
Kapp was hired by AOL's influential news site in April as senior vice president global strategy, marketing and communications.
Kapp did not immediately respond to calls for comment.
Before joining AOL, Kapp spent a decade at NBC Universal where she was the top communications executive and a member of NBC News president Steve Capus' inner circle. She was instrumental in promoting and branding some of the news division's most popular programs including "Today," "Nightly News with Brian Williams" and "Meet the Press."
The differences between NBC and the Huffington Post are vast: NBC is part of a huge corporate conglomerate controlled by cable operator Comcast Corp and its news division has a long, storied history.
The Huffington Post, founded in 2005, is a scrappy upstart that has rewritten the rule book in how news is presented and consumed on the Internet with its mixture of aggregation, heavy use of photos, original reporting and commentary.
In 2011, AOL acquired the Huffington Post for $315 million. Under the wing of AOL, the Huffington Post has expanded internationally and editorially with a masthead with boldface names such as former New York Times editor Timothy L. O'Brien and former Newsweek political correspondent Howard Fineman.
This year it won one the most prestigious award in American journalism, the Pulitzer Prize, for David Wood's series about the challenges facing wounded American soldiers coming home from war.
NBC attempted to buy the Huffington Post before AOL made the blockbuster acquisition. "We tried for the last 18 months at NBC to buy the Huffington Post; we could never agree on price is why it never got done," Former NBC Universal CEO Jeff Zucker said in February 2011.
(Reporting By Jennifer Saba; Editing by Phil Berlowitz)