 The Federal Trade Commission has requested additional information and documentary materials from Amazon.com Inc. AMZN, 0.91 and Roomba parent iRobot Corp. IRBT, 0.83 relating to their planned merger, according to a regulatory filing on Tuesday. The companies expect to promptly respond to the request, which will extend the waiting period imposed by the Hart-Scott-Rodino Antitrust Improvements Act until 30 days after they have complied. 