US authorities are probing Google’s acquisition of Waze, the social GPS app it recently bought for more than $1bn (£648m). Google confirmed over the weekend that the Federal Trade Commission (FTC) is investigating the deal on competition grounds, just months after the regulator sewed up an investigation into Google’s search practices. The FTC is concerned that the acquisition will tighten Google’s already-strong grip on the internet mapping market. When Google announced the deal earlier this month, it pledged to keep Waze independent, although its traffic-monitoring data will be incorporated into Google’s maps. Waze, a smartphone app founded in Israel, uses a mobile’s geo-location data to report on traffic conditions.