Exxon Mobil, which owns Fort Worth's XTO Energy, said North America may be able to export 15 percent of its natural gas output and 5 percent of oil by 2040 as the region's production surges and demand stalls.North America probably will become a net energy exporter by about 2025, after importing 35 percent of its oil in 2010, Irving-based Exxon said in an energy outlook report released today. Asia Pacific countries may import almost 40 percent of their total energy needs by 2040 as demand increases."After decades of relatively flat production, output of oil and other liquid fuels in North America is projected to rise by about 40 percent from 2010 to 2040," Exxon said in the report. Meanwhile, "overall U.S. energy consumption is expected to gradually plateau and then decline by about 5 percent from 2010 to 2040."Technological advances have helped tap oil and gas from shale-rock formations, as well as extracting it from oil sands and deep-water prospects in North America. Monthly U.S. oil production exceeded 7 million barrels a day in November, for the first time in 20 years. The International Energy Agency said in November the U.S. is poised to surpass Saudi Arabia as a crude producer in the next decade.More use of natural gas instead of coal and increased output from nuclear and renewable energy sources will reduce U.S. greenhouse-gas emissions, Exxon said. Carbon-dioxide emissions may drop more than 25 percent by 2040 to the lowest levels since the 1970s, the company said.In December, Exxon released a broader report with its global energy outlook, boosting its long-term estimate for worldwide demand growth to 35 percent from 32 percent as expanding populations in Africa and India use more electricity.