In a blow to Google’s efforts to crack the display-ad market, former Doubleclick CEO David Rosenblatt (pictured, right) has said he is moving on, The New York Times (NYSE: NYT) reports. Rosenblatt joined Google (NSDQ: GOOG) last year after it bought his company for $3.3 billion. During its most recent earnings call, Google executives said that the integration of Doubleclick with Google was “coming along pretty nicely.” In October, Rosenblatt took on the title of president of global display advertising.

SEE ALSO: Google Names Rosenblatt Head Of Display, Releases Build-Your-Own Display Ad Platform

Rosenblatt is the latest of several top executives, including top ad-sales exec Tim Armstrong and Asia-Pacific and Latin America president Sukhinder Singh Cassidy, to leave Google in recent months. It is not clear why Rosenblatt is leaving, although the NYT suggests he eventually wants to run his own company again. Rosenblatt’s departure also follows the appointment of Dennis Woodside to succeed Armstrong as Google’s head of sales. Rosenblatt was rumored to be a candidate for that post.