One of Australia's biggest fund managers, Kerr Neilson, has four times more money invested in China than the United States, as he bets the mainland's debt problems won't derail the economy.

Ignoring recent downgrades from credit rating agencies and warnings about the growing risk of a banking crisis, the chief executive and founder of Platinum Asset Management said the Chinese economy would surely slow next year, but he can't see anything to "stop it dead".