Japanese share prices tumbled to a 16-year low yesterday as new fears erupted about the financial health of the country's troubled banks and the outlook of the world's second-largest economy. The Nikkei 225, the key stock market indicator, closed at 11,609.63, its lowest level since January 1985 or before the asset "bubble" that Japan experienced in the late 1980s. The decline was led by a sharp fall in banking stocks, which tumbled more than 5 per cent during the day.