Getty Images and Shutterstock, two of the top photo, video and stock image marketplaces, called off a $3.7 billion merger after hitting a regulatory roadblock in the United Kingdom. Getty, led by CEO Craig Peters, said on Tuesday that its board of directors unanimously decided to scuttle the deal to merge with its rival after the top regulator in the U.K., the Competition and Markets Authority, required the sale of Shutterstock’s editorial business. Getty’s board viewed that requirement as an apparent non-starter, per a regulatory filing with the Securities and Exchange Commission on Tuesday. The board also stated it intends to hire a financial advisor to assess “strategic financing alternatives available” in its next steps. Getty provides wire service images and video to media and businesses globally, including for most red carpets and film festival premieres.…