WASHINGTON—Amazon.com Inc. on Thursday said it had closed its $8.5 billion deal to buy MGM, combining the fabled moviemaker behind “Rocky” and James Bond with the online retailing giant as it looks to draw consumers through more streaming video. In a statement, Amazon said it would welcome all MGM employees to the company and work with the studio’s leadership, indicating there would not be layoffs. Its decision to close comes after a deadline passed for the U.S. Federal Trade Commission to challenge the deal. The Seattle-based retailer announced the transaction in May 2021, saying MGM offered a trove of content to draw consumers to its fast-shipping and streaming club Prime, which costs $14.99 per month in the United States. Nearly a year later, Amazon is clear of regulatory hurdles. The European Commission approved the deal Tuesday, with no conditions. Likewise, Amazon earlier informed the FTC that it had “substantially complied” …