Google president of display ads to leave company

* Google's head of display ads David Rosenblatt resigns

* Third Google sales exec to leave since March

SAN FRANCISCO, April 29 (Reuters) - The president of Google Inc's (GOOG.O) global display advertising business is leaving, marking the latest in a series of changes within the Internet company's sales team in the past two months.

David Rosenblatt, who joined Google last year through its $3.1 billion acquisition of DoubleClick, has resigned and will leave the company in mid-May, a Google spokeswoman said on Wednesday.

Rosenblatt was the CEO of DoubleClick, which Google bought to bolster its position in the Internet display advertising business.

The bulk of Google's revenue, which totaled $5.51 billion in the first quarter, comes from text-based ads, which appear alongside Google's search results, say analysts.

RBC Capital Markets analyst Ross Sandler said Rosenblatt and the other departing Google sales executives "carried a significant amount of weight in the industry, especially with ad agencies."

But he said Google has a deep bench of executives who should be able to fill their shoes.

In March, Google's head of Americas sales Tim Armstrong left the company to take the CEO job at Time Warner Inc's (TWX.N) AOL [ID:nN12403727]. Earlier this month, Sukhinder Singh Cassidy, the president of Google's Asia-Pacific and Latin America operations, left to join a venture capital firm.

Google also announced this month that sales chief Omid Kordestani was moving into a new role, as senior advisor to the office of the CEO and founders.

While the back-to-back nature of the departures in Google's sales team is surprising, RBC's Sandler said the moves appeared to reflect the individuals' situations rather than anything about Google's business.

Rosenblatt, he said, had been at DoubleClick for 12 years and Google's integration of DoubleClick is complete.

"I think these are pretty easily explainable cases of very wealthy individuals looking for new challenges," Sandler said.

Shares of Google rose 2.1 percent to $391.90 on Nasdaq late Wednesday afternoon. (Reporting by Alexei Oreskovic; Editing by Richard Chang)