Warren Buffett made the call, the Financial Times reports:
Two people close to the talks said Warren Buffett and 3G's Jorge Paulo Lemann, the major Heinz Kraft shareholders, decided on Sunday morning to withdraw the bid after they concluded that a protracted public battle to take over Unilever would have caused more damage than good.
News of the possible deal, which at $143 billion would have been one of the biggest ever, broke Friday, when Unilever rejected it. Kraft vowed to press on, but the damage was done. More from the FT:
Another person said that the early leaking of Kraft's interest in Unilever made it hard for the US company to negotiate a deal that would have been more attractive for both sides. "Kraft Heinz was ready to make a lot of concessions, including taking on the Unilever name, to make this deal happen but unfortunately it leaked too early and that made it hard negotiate," this person said.