A company spokesman said Mr. Weber quit his position Aug. 2 effective immediately.
Mr. Weber joined the South Korean car importer in the fall of 1998 and "was a key contributor to the company's turnaround," Finbarr O'Neill, president-CEO, said in a statement.
Mr. Weber couldn't be reached for comment.
Hyundai changed media and
Hyundai spent $169.7 million in measured media last year, 17.1% more than in 2000, according to Taylor Nelson Sofres' CMR.
Mr. Weber's departure follows last week's sudden resignation of Rick Weisehan, marketing director of Hyundai's sibling Kia Motors America. No successors have been announced for either marketing executive.