US e-commerce giant Amazon is abandoning its plans to purchase the robot vacuum cleaner manufacturer iRobot following opposition from competition regulators. The European Commission, for instance, said it saw a risk of Amazon reducing the prominence of similar rival products in the search results on its site. The cancellation of the deal has immediate consequences for Massachusetts-based iRobot. The company said almost a third of its 350 employees are now due to be let go and long-time boss Colin Angle is retiring. The takeover was initially valued at $1.7 billion when it was announced in Augu…