Houston leaders have approved a 25-year use and lease with Southwest Airlines Co. in another step toward making the city's William P. Hobby Airport an international facility for the carrier.

The Houston City Council on Wednesday approved the deal. Dallas-based Southwest seeks to become an international carrier since its 2010 acquisition of AirTran Airways. Officials have yet to determine which foreign cities would be served by Southwest.

The Houston Chronicle reports officials expect to break ground this summer on a two-story, five-gate concourse and Customs and Border Protection inspection facility.

Southwest spokesman Paul Flaningan says the carrier has already paid for the $150 million expansion scheduled for completion in 2015.

Southwest won't pay rent at the new gates. Houston will get revenue from running the concourse's food vendor sites.