His duties will amount to his controlling all non-subscription revenue.
Jonesco replaces Ian Ward, who is leaving the company to pursue an MBA.
Jonesco will report to Mindy Mount, the executive vice-president and co-managing director of AOL's UK operations.
"We are delighted to have someone with such substantial experience and knowledge of UK media sales driving our interactive marketing function," Mount said. "AOL is committed to making online a true mass-market medium."
"Online should no longer be regarded by advertisers as new media, simply as media, and I am looking forward to working with the team here at AOL to make that happen,