Google to acquire ad firm DoubleClick for $3.1b

Seeking to expand its already well-honed ability to sell targeted Internet advertisements, online search leader Google has agreed to pay $3.1 billion in cash to acquire ad-management technology company DoubleClick, an Associated Press report said.

The Associated Press report also said the two companies announced the deal after the markets closed last week.

The boards of both companies have approved the takeover, which is expected to close by the end of the year, the report said.

New York-based DoubleClick helps its customers place and track online advertising, including search ads, which Google has turned into an extremely lucrative business, the report said.

DoubleClick had been the target of a fierce bidding war between Microsoft and Google, and Google's winning bid is nearly three times the amount DoubleClick fetched when it went private in 2005 for $1.1 billion, the report said.

The acquisition is the largest in Google's history, beating out the $1.76 billion deal for online video-sharing site YouTube late last year, the report further said.