(Adds potential for reduction in global production if other countries also impose moratoriums) By Mari Iwata Of DOW JONES NEWSWIRES FUKUI, Japan (Dow Jones)--Global oil output could fall up to 900,000 barrels a day from projected levels for 2015 if oil producing countries follow the U.S. lead and impose moratoriums on development of new offshore oil reserves, International Energy Agency Executive Director Nobuo Tanaka said Friday. The Paris-based organization is conducting research on the possible impact of the U.S. moratorium and its implications worldwide, Tanaka said. "If other countries like Angola, Brazil and the North Sea (countries) put on hold new offshore development and there is also one or two years of delay, the impact on global oil output might be 800,000 barrels a day-900,000 barrels a day by 2015," Tanaka told Dow Jones Newswires in the western Japanese city of Fukui, where he will participate in an Asia Pacific Economic Cooperation group energy ministers' meeting that starts Friday evening. Although it would represent a mere 1% or so of global oil output, "given that spare oil production capacity is about 6 million barrels a day, (a reduction of) roughly 1 million barrels a day can't be ignored," he said. Earlier on the day, Australia's Energy Minister Martin Ferguson vowed to act swiftly on the findings of an official investigation into the cause and handling of PTT Exploration & Production PCL's (PTTEP.TH) oil spill last year at the Montara field in the Timor Sea, off northern Australia. Oil and gas companies began shutting down 33 deepwater exploration rigs last month after U.S. President Barack Obama imposed a six-month moratorium on developing new deepwater wells in the Gulf of Mexico. "There is little near-term impact. But for the medium term, if new offshore oil development in the U.S. is delayed by one or two years, the impact (on production) would be 100,000 barrels a day-300,000 barrels a day by 2015," Tanaka said. "The ultimate impact is unclear. But it would take time to investigate the causes of the spill and develop appropriate safety requirements and procedures," he said. The Obama administration wants clear requirements in place before any more drilling proceeds, to avoid another catastrophic spill. At the three-day APEC meeting, ministers and government officials will discuss energy security, sustainable development of energy resources and the adoption of renewable sources. -By Mari Iwata, Dow Jones Newswires; 813-6269-2798; [email protected] (END) Dow Jones Newswires June 18, 2010 04:02 ET (08:02 GMT)