Australia has lost substantial market share in China in coal, its biggest export commodity, partly because of the severe port and rail infrastructure bottlenecks, which have plagued its overheating economy in recent years.

China, the world’s largest coal consumer, reduced its imports from Australia by 34 per cent to 4.52m tonnes last year, according to figures released on Tuesday in Beijing by the Chinese customs authorities. Vietnam was its biggest foreign supplier, with sales jumping 23 per cent to 24.6m tonnes.