Iron ore shipments from Australia’s Port Hedland, the world’s largest bulk-export terminal, expanded to the third-highest level on record, signaling that a global surplus is set to persist. Exports totaled 39.4 million metric tons last month from 37.7 million tons in April and 38 million tons a year earlier, according to data from the port authority. Shipments were a record 39.5 million tons in March. Cargoes to China were 31.7 million tons in May compared with 32.6 million tons in April and 31.7 million tons in May 2015. Goldman Sachs Group Inc. said it expects a growing surplus of seaborne supply in the coming months to pummel prices, according to a May report. Benchmark prices sank back below $50 last week to the lowest since February on concern that profit margins at China’s steel mills are again tumbling, hurting the outlook for iron ore demand just as miners continue to add supply. “Australia’s exports have been steady at high levels and will probably remain so for the rest of 2016 as miners boost output,” Wu Zhili, an analyst from Shenhua Futures Co., said by phone before the data. “This may add to signs of a swelling glut in China, where demand is past the seasonal peak. Exports may continue to push up port inventories in China.” Port Stockpiles Iron ore posted the biggest monthly loss in about five years in May, sinking 24 percent, according to Metal Bulletin Ltd. Ore with 62 percent content in Qingdao rose 2.8 percent to $52.54 a dry ton on Tuesday. That’s still well shy of April’s high of $70.46 a ton. Port Hedland handles cargoes for miners including BHP Billiton Ltd., Fortescue Metals Group Ltd. and new entrant Roy Hill Holdings Pty. Shipments through the port represented 58 percent of Australia’s total iron ore exports last year. Port inventories in China have increased 7.7 percent this year to 100.25 million tons last week, near the highest since December 2014, according to data from Shanghai Steelhome Information Technology Co. BHP forecast last month there may be further increases. Demand from China has been stronger than expected amid government efforts to prop up the economy, according to Citigroup Inc., which has raised its price forecasts for the raw material. Iron ore will trade at $48 a ton in the third quarter and $46 in the final three months, compared with previous estimates of $46 and $38, the bank said Tuesday.