SHANGHAI, May 21 (Reuters) - Australian exports of iron ore to China surged 45.8 percent in April from a year earlier, customs data showed on Wednesday, with the country's miners pushing ahead with expansion plans to meet demand from the world's top consumer.
Monthly shipments imported by China from Australia reached 47 million tonnes in April, amounting to 56.4 percent of the total volume of 83.39 million tonnes, the second highest on record.
The rapid increase came amid weaker iron ore prices, with the country's miners, including Rio Tinto and BHP Billiton , all in the middle of plans to expand production capacity on expectations of rising Chinese demand.
Despite plunging prices and worries that growth in demand could be running out of steam, Chinese steel production has also remained at record levels, with output from large mills hitting a record high of 1.824 million tonnes per day in the first 10 days of May.
But increased iron ore supply has also brought stockpiles at major Chinese ports to record levels above 110 million tonnes, weighing on prices .IO62-CNI=SI, which have already fallen 27 percent so far this year.
Brazil's Vale, the world's top producer, is on course to increase annual iron ore output to 450 million tonnes by 2018, from 306 million tonnes last year, while third-ranked BHP Billiton is set to increase its annual capacity to up to 270 million tonnes from a forecast 217 million tonnes this year.
Global iron ore suppliers are expected to bring in total additional capacity of 240 million tonnes this year and next, Vale has estimated.
Australia has exported a total of 165.2 million tonnes of the steelmaking raw material to China in the first four months of 2014, jumping 35 percent from the same period last year.
Brazil, the second-largest exporter of the commodity, shipped 14.1 million tonnes of iron ore to China in April, up 12 percent on the year. Its total shipments rose about 10 percent to 55.7 million tonnes in the first four months from a year ago.
Reporting by Ruby Lian and David Stanway; Editing by Joseph Radford