Market leader Southwest Airlines fell 4.2 percent to 1.4 million passengers in June, and No. 2 US Airways was off 37.9 percent to 422,411. No. 3 United was down 4.2 percent to 247,690. In Las Vegas, the two busiest airlines have cut capacity while Nos. 3, 4 and 5 have added. US Airways, which cut its night-hub operations in Las Vegas last year, has trimmed capacity 37 percent since June 2008. Southwest's capacity is down 5.2 percent over the same period. Meanwhile, United's capacity is up 4.6 percent, American's is up 10.7 percent and Delta's is up 3.7 percent. Delta is in the midst of a merger with Northwest Airlines, which cut capacity by 4.6 percent in Las Vegas. Las Vegas-based Allegiant Air, the No. 7 carrier at McCarran, continues to gain on No. 6 Continental with 182,620 passengers in June. For six months, Allegiant has served 951,199 passengers compared with Continental's 972, 242.