ValueClick Inc. has acquired London-based Shopping.net for approximately $13.3 million in cash.

Shopping.net operates a network of 27 Web sites that reportedly generate $4 million in revenues annually through pay-per-click advertising. It attracts more than 2 million unique visitors per month. The firm also offers search-marketing services to European consumers.

"This acquisition expands our online shopping destination site presence and is significant step in our European expansion," said in a statement Carl White, CEO of ValueClick Europe.

ValueClick has plans to integrate Shopping.net's online services with its existing online services in Europe. Shopping.net is ValueClick's second European acquisition. It acquired comparison-shopping site PriceRunner.com in 2004.