Rosenblatt will leave Google in mid-May having joined only last year when the search giant bought internet ad firm DoubleClick for $3.1bn last year. Rosenblatt had been the CEO of DoubleClick where he spent 12 years.
Google, in a statement, said: "It's important to remember that we have a strong executive leadership bench in place to support all our businesses, and have tapped into that bench."
He is being replaced by Henrique De Castro, managing director European sales and media platforms, which included Google and YouTube.
Rosenblatt was the CEO of DoubleClick, which Google bought to bolster its position in the Internet display advertising business.
The departure of Rosenblatt follows that of Google's head of Americas sales Tim Armstrong left the company to join AOL as its new global chief executive.
Sukhinder Singh Cassidy, the president of Google's Asia-Pacific and Latin America operations, also left earlier this month.
Earlier this month Google reported revenues for the quarter ended March 31 were down 3% at $5.51bn, though still up 6% year on year.
In March Google revealed it is to cut roughly 200 sales and marketing positions globally after revealing it had over-invested in some areas of its business.