The guessing who will buy advertising company DoubleClick has an end. Google Inc. announced today a definitive agreement to acquire DoubleClick Inc., for $3.1 billion in cash from San Francisco-based private equity firm Hellman & Friedman along with JMI Equity and management.

"It has been our vision to make Internet advertising better - less intrusive, more effective, and more useful. Together with DoubleClick, Google will make the Internet more efficient for end users, advertisers, and publishers," said Sergey Brin, Co-Founder & President, Google Technology.

Google identified these advantages of the deal:

• For users, the combined company will deliver an improved experience on the web, by increasing the relevancy and the quality of the ads they see.
• For online publishers, the combination provides access to new advertisers, which creates a powerful opportunity to monetize their inventory more efficiently.
• For agencies and advertisers, Google and DoubleClick will provide an easy and efficient way to manage both search and display ads in one place. They will be able to optimize their ad spending across different online media using a common set of metrics.