ValueClick said Thursday it had agreed to acquire Fastclick in a stock swap valued at about $214 million, giving ValueClick access to Fastclick's advertising network of more than 9,000 third-party websites reaching over 112 million U.S. users, reports the AP. Fastlick's ad network served 27 billion impressions last quarter, and the companies say the merger will make ValueClick the largest online ad network provider, writes ClickZ. After the deal is consummated in the fourth quarter, Fastclick will operate as a unit of ValueClick.

Known as the largest player in affiliate marketing, ValueClick has expanded into search, email marketing and comparison shopping through acquisitions - including BeFree in 2002, Commission Junction in 2003, PriceRunner.com in 2004, E-Babylon and Web Clients in June of this year. And, apparently, more such moves are in the offing.

ValueClick chairman and CEO James Zarley is quoted by ClickZ as saying, "We expect a straightforward integration of Fastclick - headquartered across the street from our Commission Junction office in Santa Barbara - to quickly realize operating synergies."

ValueClick said it expects to save about $4 million annually in operating costs after the merger.

Fastclick shareholders will receive 0.7928 ValueClick shares for each common share they own. ValueClick will issue about 15.6 million shares to complete the transaction, which values Fastclick at $10.11 per share - a 14 percent premium to the stock's Wednesday closing price.