The US Federal Trade Commission regulators approved the merger with a 4-1 vote. The Commission determined that the $3.1 billion deal is “unlikely to substantially lessen competition. However, the deal still faces some challenges in Europe and potentially other places in the world. [via Wall Street Journal]

Valleywag comments that it might very well have been Microsoft’s large advertising deals that convinced the regulators that the online ad business is as competitive as Google has argued all along. However, there is no real evidence to support the claim.

Update: Mashable coverage