Standard&Poor's Ratings Services affirmed its 'A' rating on the City of Austin, Texas' airport system revenue bonds. The outlook is stable. The rating reflects what we view as the following credit factors: The airport has a strong origin and destination (O&D) market (95%) and good diversity of carriers with Southwest Airlines Co. (BBB-/Stable), United Air Lines Inc. and Continental Airlines Inc. (now combined; B/Stable), and American Airlines Inc. (D/--) accounting for 75% of enplanements in 2011; Solid enplanement growth, with passenger traffic increasing at an average annual rate of 3.1% in the past nine years to reach 4.55 million enplaned passengers in 2011; and The airport's service area benefits from a strong economy with a low unemployment rate,
