Google has signed an agreement to acquire Admeld, a New York-based yield optimization firm.

Google did not disclose the financial terms of the deal. Last week, TechCrunch reported last week that Google paid roughly $400 million, citing anonymous sources.

New York-based AdMeld provides "yield management" technology, which allows Web publishers to instantly sell display ads, as Web surfers visit different pages on a site.

"Some publishers work with a "yield optimization" provider that supplies technology to select ads from across these many indirect options, while providing personalized service and support. In a very complex and rapidly growing display ad landscape, that's what Admeld does," said Neal Mohan, Vice President of Display Advertising at Google.

Formed just over three years ago, the Admeld team has developed a service that is helping many major publishers manage their ad space more efficiently and profitably.

By combining Admeld's services and technology with Google's offerings, Google is investing in what its hopes will be an improved era of flexible ad management tools for major publishers.

"Together with Admeld, we hope to make display advertising simpler, more efficient and more valuable, provide improved support and services, and enable publishers to make more informed decisions across all their ad space," Mohan added.

Admeld will continue to support other ad networks, demand side platforms, exchanges and ad servers.