WASHINGTON — A planned merger between Southwest Airlines and AirTran Airways is expected to put more stress on U.S. airports, especially those that rely on either or both of the discount carriers for bond-related revenue, Moody's Investors Service warned in a report this week.

The rating agency has a negative outlook on the U.S. airport sector because of the poor economy and lackluster air travel activity.

Subscribe Now

Independent and authoritative analysis and perspective for the bond buying industry.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.