DALLAS (AP) — Most major U.S. airlines sharply scaled back their latest price increase on routes where they compete with low-fare giant Southwest, which declined to go along with the higher fares. Delta Air Lines Inc., for example, dropped a $10 round-trip increase on about 60 percent of the routes where it hoped to boost prices, JPMorgan Chase analyst Jamie Baker said Monday. The airlines have raised base prices and business fares several times in 2011 as they struggle with higher fuel costs.