BHP Billiton Ltd., the world’s biggest mining company, said first-quarter iron ore output fell 3 percent on planned maintenance and a fire at its Mt. Whaleback operation in Australia, though expects to meet its full-year target. Output was 55.6 million metric tons in the three months ended Sept. 30, from 58 million tons a year earlier, Melbourne-based BHP said Wednesday in a statement. That missed a 58.8 million tons median estimate among four analysts surveyed by Bloomberg. Full-year output from its Australian mines, including third party tons, remains on course to rise to a range of 275 million to 280 million tons in fiscal 2018, BHP said. Rio Tinto Group on Tuesday reported it was on track for 2017 shipments of 330 million tons after quarterly cargoes jumped 6 percent on higher rail capacity. Imports by China surged to a record in September, topping a previous high set in 2015, as the world’s top steelmaker’s drive to boost air quality stokes demand for imported higher-grade and less-polluting raw materials. Copper production surged 14 percent to 404,000 tons, boosted by the ramp up of the Los Colorados Extension project at Chile’s giant Escondida mine, BHP said. Output at the operation hit a more than two-year high in August, according to Chile’s government. The data showed a solid result for BHP, with “higher copper output helping to offset lower iron ore volumes out of the Pilbara” iron ore unit, Melbourne-based RBC Capital Markets analyst Paul Hissey said in a note. BHP declined 0.8 percent to A$27.10 at 10:58 a.m. in Sydney trading Wednesday, as the benchmark S&P/ASX 200 Index gained 0.1 percent. The company had agreed in the September quarter to sell a “small portion of the Hawkville acreage” in its shale unit, BHP said in the statement, without providing details. “Work is underway to exit the remaining onshore U.S. assets for value.” BHP is in talks with potential buyers, Chief Executive Officer Andrew Mackenzie said in an August interview. BHP’s shale operations, acquired in a $20 billion string of deals in 2011, have been a focus for investor concern and among targets in an activist campaign led by Elliott Management Corp., which is seeking a wider review of the oil unit. BHP’s new Chairman Ken MacKenzie is scheduled to publicly address shareholders for the first time Thursday at a London annual meeting. Petroleum output declined 8 percent to 50 million barrels of oil equivalent, which beat a 48.3 million barrel median estimate among five analysts surveyed by Bloomberg. Production at BHP’s onshore oil and gas assets in the U.S. tumbled 16 percent.