"Economically, it would be bad news, bad news for the United Kingdom, as well as the world, not just Europe," Hollande told a news conference after the conclusion of a Group of Seven leaders’ summit in Japan.
"That would trigger capital transfers as well as the relocation of some activities that would not be for the benefit of the United Kingdom or even for Europe," he said, Reuters reported.
Britain will decide in a referendum on June 23 whether to stay in the EU or leave the 28-country bloc.