at the time of its shutdown, ata airlines had a codeshare agreement with southwest airlines. as far back as 2001, ata explored a passenger sharing agreement, with a now defunct airline called access air which also had midwestern united states flight operations. this agreement was short lived due to the tedious economic condition of this post deregulation "start up" carrier. the ata connection service flown by commuter air carrier chicago express airlines was also operated on a codeshare basis.