Adknowledge said today it has raised $200 million in debt and private equity to pursue acquisitions. The company runs a big ad network and handles special ads known as offers.

Adknowledge plans to use the money to expand its ad network worldwide so that its advertisers can reach users in the mobile, video, content, and display markets. In other words, just about everyone that the internet reaches.

Kansas City, Mo.-based Adknowledge said it has doubled its revenue over the past 12 months through acquisitions and internal growth. The company said it is the largest privately owned internet ad network in the U.S., with more than 330 employees and $300 million in revenue.

JMI Equity, a private equity firm, led this latest investment, while Bank of America led the debt financing.

Adknowledge operates a long-tail marketplace, www.bidsystem.com, for advertisers who are looking to syndicate their ads into different types of non-search markets. It can target either cost-per-click or cost-per-action models. That is, it can funnel advertisers into banner ads or into special offers, where a user can accept an offer such as watching a film clip instead of paying for an item. More than 10,000 advertisers use Adknowledge to target hard-to-reach segments such as casual games, email, social networks, display ads, mobile ads, and others.

“It’s easy to advertise with Google, Bing and Facebook, but much tougher to reach the rest of the Internet because it’s so fragmented,” said Adknowledge CEO Scott Lynn.

Adknowledge was founded in 2004 and has acquired firms such as Miva, Super Rewards and Hydra. It competes with companies such as Tapjoy in offers and others in ad networks.