A plan by Southwest Airlines to bring international service to Houston’s Hobby Airport (HOU) advanced a step last week, despite objections from United.

Southwest has asked for city approval to build a five-gate international terminal at Hobby, and Houston Director of Aviation Mario Diaz last week sent a recommendation to the city’s mayor that Southwest be allowed to move ahead with the project. The proposal still requires city council and federal approval.

Southwest has a major domestic operation at Hobby, with 134 flights a day, and now it wants to provide “a low-fare alternative to destinations in Mexico, the Caribbean, and cities in Central and South America” from the airport, the airline said in a statement. Southwest is trying to drum up consumer support for the idea through a new website at www.freehobbyairport.com.

In his report to the mayor, Diaz said that given the size of Southwest’s domestic network at Hobby, “it would not be reasonable to require the airline to relocate to Bush Intercontinental Airport (IAH), or even conduct split operations – domestic service at Hobby and international service at Intercontinental. Therefore it’s my recommendation we support Southwest’s request to begin the process of obtaining the necessary approvals to initiate international service at Hobby.”

He said two independent studies commissioned to look into the issue concluded that opening up international service at Hobby would generate an additional 1.5 million travelers to, from and through Houston each year, with an economic impact of $1.6 billion.

However, United Airlines is challenging the validity of the studies and is telling the city that the execution of Southwest’s plan would result in serious harm to Houston Bush Intercontinental Airport – not coincidentally, the site of a major United hub with a virtual monopoly on international service for the Houston market.