Fitch Ratings downgraded Dallas-Fort Worth International Airport on Friday because of new borrowing to finance improvements to terminals.
Fitch lowered $4.7 billion in older DFW bonds to "A" from "A+" and gave "A" ratings to $736 million in new bonds issued by Dallas and Fort Worth on behalf of their airport. Fitch gave the outlook for all the bonds as "stable."
"The rating downgrade reflects the sizable increase in airport borrowings to fund DFW's terminal renewal and improvement" projects, Fitch said, adding that two programs will cost more than $4 billion and boost the airport's debt to more than $6.5 billion.
The airport did not immediately respond to a request for comment.
DFW's main tenant is American Airlines, which filed for bankruptcy protection in November 2011. American's parent, AMR Corp., has announced plans to merge with US Airways Group Inc. Leaders of the combined company have promised to keep American's DFW hub.
Fitch noted that since the bankruptcy filing American hasn't sought to change any of its agreements with DFW Airport, but said that "uncertainty remains as to the impact the merger will have on operations at DFW."