Las Vegas-based Allegiant Air LLC, which operates three weekly flights between Redmond and Las Vegas, carried 281,977 passengers throughout its system in June, the airline announced Friday. That was up 57.5 percent from June 2006. To date, Allegiant has served 753,716 passengers in 2007, up 58.3 percent from the first six months of 2006. Allegiant is one of three commercial carriers offering service at Redmond Airport.