The Dallas-based carrier will begin using the new ''D'' concourse. It includes eight gates, a six-lane security checkpoint and additional concessions shops.
''These eight new gates will give Southwest room to grow at Sky Harbor and will accommodate the growth we anticipate at the fifth busiest airport in the world,'' said Gary Kelly, Southwest's chief executive officer.
Southwest also will operate 16 gates in concourse ''C'' but will no longer use the ''B'' concourse.
With the new facility, Southwest will expand a sharing agreement with ATA Airline.
The agreement allows Southwest and ATA to exchange passengers flying to Maui and their checked baggage at Phoenix Sky Harbor Airport. Through the codeshare option, passengers can book service through either carrier and transfer in Phoenix from Southwest to ATA for the remainder of the trip by using a single ticket.
The codeshare service will be available in Albuquerque, Austin, Nashville, Houston Hobby, Chicago Midway, Oklahoma City, Omaha, Providence, Raleigh/Durham, and St. Louis.
Codeshare service with ATA flights in Phoenix for continuation to Honolulu is already offered from Albuquerque, Austin, Birmingham, El Paso, Houston Hobby, Islip Long Island, Raleigh/Durham, and Salt Lake City.
