Google continues to make huge strides in its attempt to corner the global market for advertising sales and delivery with a mega-deal to sell and deliver commercials for Clear Channel’s 675 radio stations.

The Internet search giant has entered a multi-year agreement that guarantees it the right to auction online a significant chunk of broadcaster’s commercial inventory.

John Hogan, CEO of Clear Channel Radio says it is a “win-win” for both companies.

“Clear Channel Radio gets access to an entirely new group of advertisers within a new and complementary sales channel, and Google adds another option for its existing customers. Google has proven its ability to gain premiums for advertising inventory and that fits perfectly into our broader strategy of building value for advertisers while increasing our overall revenue yield. We’re committed to working with the best-in-class and Google has a real economic incentive to produce meaningfully higher CPMs.”

Expectation within the radio industry is that exactly the opposite may be true, and that Google’s auction based model could potentially lower the current CPM, or cost per thousand impacts.

Clear Channel says its current national and direct sales teams will continue to focus on current relationships, and the deal focus is to grow radio advertising for clients who currently use online.

Interestingly, the announcement comes at a time when Bain Capital and Thomas H Lee Partners are in the process of taking the company private, and almost certainly looking for ways of trimming costs further.

Clear Channel is already renowned for razor-thin programming budgets and nationwide networking; a reduction in sales force and administration staff could potentially be a significant cost-saving measure for the company.

Google also announced Saturday (Australian time) it had purchased the largest Internet advertising syndicator DoubleClick, for US$3.1 billion in cash.