A $143 billion bid by Kraft Heinz to buy Unilever was rejected Friday. A combination would be the third-biggest takeover in history and the largest acquisition of a UK-based company, according to Thomson Reuters data. The potential takeover would fuse some of the world's best known brands, from toothpaste to ice creams. Kraft has until March 17 to make a final bid for Unilever, whose stock rose to a record following the news of a potential takeover, under UK takeover rules.