America Online Tuesday announced that it has acquired Sphere Source, a provider of contextual-search tools that offers related content to publishers.

The US-based Sphere, which was founded in 2005, will operate as a wholly owned subsidiary of AOL as part of the company's Programming division, according to the statement.

Sphere's search technology allows Web publishers to enhance their Web pages by linking to articles, blog posts, video, photos and other related content. Sphere had already been offering its widget technology on AOL News and the myAOL service.

"Our focus at AOL is providing consumers relevant content wherever they are on the Web, and Sphere's capabilities fit in perfectly with this effort. Not only will it let us enhance content on our own sites, it will let us distribute our content across Sphere's growing third-party publisher network," said Ron Grant, President and COO of AOL, in the statement. "In addition, this acquisition provides AOL with access to advertising inventory across Sphere's network, while growing its reach to content publishers via the widget."

Financial terms of the deal were not disclosed.

"Unlike the rumor that Sphere has reserved the Wrigley Field bleachers for Game 7 of the 2008 World Series, the conjecture about Sphere being acquired by a larger platform is officially true. AOL has acquired sphere," said Sphere CEO Tony Conrad, in a blog post. "We think it's a huge advantage to become part of a suite of services that understands how Internet users access/consume content, and how to intelligently monetize in tandem with that content. This is a win-win for our partners, AOL and Sphere."