L.E.K. Consulting will present its findings at a Dallas City Council transportation committee hearing at 1 p.m. on Monday.
"Southwest is the most attractive option for the City of Dallas, given both expectations for its [origin and destination passengers] throughput and potential for low fares," the report said.
Virgin America and Delta Air Lines are also interested in the gates that American is required to divest as part of its merger settlement agreement with the U.S. Department of Justice.
On Friday, Virgin America announced it had an agreement with American to take over the lease of those gates and began selling tickets on flights to five cities out of Love Field. The agreement, Virgin America said, is pending approval by the city of Dallas.
"While both Southwest and Virgin would serve substantial passengers, Virgin would be removing flights from DFW," the report said.
Virgin America currently serves two cities out of Dallas/Fort Worth Airport and has said it intends to transfer its service from DFW to Love Field.
Photo of Southwest airplane taking off at Love Field on April 25, 2014 by Star-Telegram's Max Faulkner.