March 11 (Reuters) - U.S. oil production could become lessresponsive to crude prices as major oil companies take a largershare of the nation's shale output from smaller independentproducers, International Energy Agency officials said at anindustry summit on Monday.
Most of U.S. shale crude is produced by independentproducers. But Exxon Mobil Corp and Chevron Corplast week forecast strong production growth in the nation'sbiggest oil field, the Permian Basin of West Texas and NewMexico, which could mean output would shift to companies thatare far slower to respond to oil prices, said Toril Bosoni, asenior analyst at Paris-based IEA.(Reporting by Collin EatonEditing by Marguerita Choy)