Giphy

The United Kingdom’s antitrust watchdog has blocked Facebook’s acquisition of Giphy and ordered the social network to sell off the GIF-sharing platform, saying the deal hurts social media users and advertisers by stifling competition for animated images. The Competition and Markets Authority said Tuesday that the deal would let Facebook “increase its already significant market power” by denying or limiting other platforms’ access to Giphy GIFs and driving traffic to Facebook-owned sites. It has noted previously that there’s only one other big provider of GIFs, Google’s Tenor. The regulator also was concerned that the deal removed potential competition from the U.K.’s 7 billion pound ($9.3 billion) display advertising market, of which Facebook controls half. It’s the first time the watchdog...