Microsoft Corp. and Yahoo Inc. have received clearance from regulators in Washington and Europe to proceed with a search partnership intended to challenge Google Inc.

The companies announced Thursday that the partnership has been approved without restrictions by the Justice Department and the European Commission. Under the 10-year agreement, Microsoft's Bing search engine will process search requests and steer search-related ads on Yahoo. Yahoo is due to get 88 percent of the revenue generated from the ads placed alongside the search results on its sites.

The companies said they will begin implementing the deal in the coming days by shifting Yahoo's search platforms to Microsoft. They hope to move most advertisers and publishers before the 2010 holiday season, but may wait until 2011 if necessary, and expect to complete the process by early 2012.

This deal came about after the Justice Department indicated in 2008 that it would fight Yahoo's plan to team up with Google on search. That rejection led Yahoo to turn to Microsoft, which had once offered to buy Yahoo in its entirety.

A statement from the European Commission said the Yahoo-Microsoft partnership "would not significantly impede effective competition."