--Rise of 62 bcf in gas inventory expected in 10:30 a.m. EDT data --Build would top year-earlier rise, match five-year average build --Storm-curtailed output expected to start coming back on line By David Bird NEW YORK--Natural-gas futures were steady early Thursday, awaiting U.S. inventory data that is expected to show a sizeable increase amid easing end-summer demand. Energy Information Administration data, due at 10:30 a.m. EDT, is expected to show gas inventory rose by 62 billion cubic feet last week, keeping the stockpile at a record high for this time of year and maintaining pressure on prices. A rise of the expected size would top the year-ago build of 60 bcf and would be in line with the five-year average for the week. Hot summer weather and strong demand for gas from power generators has trimmed the level of injections into storage this summer, compared with historical levels, but high output has kept inventories growing. Gas injections haven't topped the year-earlier level on a weekly basis since mid-April, said Matt Smith, an analyst at Summit Energy. If the storage estimate is correct, inventories as of Aug. 24 will total 3.370 trillion cubic feet, about 11.8% above the five-year average and 14.4% above last year's level for the same week. October-delivery natural gas futures on the New York Mercantile Exchange were trading 0.2 cent lower, at $2.683 per million British thermal unit. Traders said prices could challenge support near $2.58/mmBtu, around the intraday low for the September contract during its expiration day on Wednesday. Government data show some 72% of U.S. Gulf natural gas output, or 3.2 billion cubic feet per day, was shut in as of Wednesday, as Hurricane Isaac moved through the region. But facilities are expected to be brought back on line quickly after inspections in coming days, if no damage is discovered. Gulf gas output accounts for just about 5% of U.S. supply, down from about 15% in 2005, amid the growth in onshore shale gas output. Jim Ritterbusch, president of Ritterbusch % Associates, said cooler temperatures and power outages resulting from the storm are offsetting much of the impact of the temporary supply loss. Natural gas for next-day delivery at the benchmark Henry Hub in Louisiana recently traded at $2.75/mmBtu, according to IntercontinentalExchange, compared with Wednesday's average of $2.65/mmBtu. Natural gas for next-day delivery at Transcontinental Zone 6 in New York traded at $2.90/mmBtu, compared with $2.81/mmBtu. Write to David Bird at david.bird@dowjones.com Subscribe to WSJ: http://online.wsj.com?mod=djnwires

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