Burger King Owner Downgraded To Sell On Signs Of Slowing Sales Growth By: TalkMarkets September 26, 2016 at 13:46 PM EDT Research firm Longbow downgraded Burger King owner Restaurant Brands to Underperform, its equivalent of a sell rating, from Neutral. Read More >> Related Stocks: Brinker International Darden Restaurants Dennys Corp Dine Brands Global, Inc. McDonald's Corp Restaurant Brands International