Yahoo!, Microsoft and AOL have signed agreements to improve the process of buying and selling premium online display inventory.

Under the agreements, the ad networks operated by Yahoo!, Microsoft and AOL will offer each other’s premium non-reserved online display inventory to their respective advertising customers, while agencies and advertisers can choose to partner across Yahoo! Network Plus, AOL’s Advertising.com and the Microsoft Media Network.

The trio partnership will offer the efficiency of buying premium display inventory at scale to reach customers and audiences, enhances the demand for and value of each party’s display advertising offerings and also provides better yield for participating publishers and advertisers.

To achieve the benefits of scale and efficiency Yahoo!, Microsoft and AOL are expected to have the opportunity to access each other’s non-reserved inventory.

Effective in the US, the partnership is based on the premise of audience-based selling across a large number of sites.

In addition to the US, Yahoo! and AOL will have an agreement that extends to Canada. Microsoft’s Canada business is not participating directly in the agreement.

Yahoo! Americas executive vice president Ross Levinsohn said Yahoo! is thrilled to partner with Microsoft and AOL and bring to market what we believe will be a more efficient, effective and more effortless way to access true premium inventory and formats.

"There has a been a significant shift in how inventory is bought and sold, and we’re now 100% focused on controlling our own destiny, working directly with marketers and agencies and driving better returns for our advertising partners," said Levinsohn.

Microsoft Advertising Business Group corporate vice president Rik van der Kooi said this partnership will create an opportunity where advertisers and publishers alike can benefit from easier access to — and demand for — high-quality inventory.

"The fact that we’re joining together to offer this kind of access to quality — yet each with our own differentiated ad offerings — is something that will benefit the market as a whole," said Kooi.

AOL chief revenue officer Ned Brody said today’s announcement sets in motion the opportunity for advertisers to achieve scaled solutions across premium publishers.

"This should reduce friction in the marketplace, which will benefit both advertisers and publishers. And this partnership will take our existing Advertising.com partnerships with both Microsoft and Yahoo! to a new level," said Brody.