BALTIMORE (Map, News) - Despite losing its partner in a deal that could have turned Baltimore/Washington International Thurgood Marshall Airport into its international hub, Southwest Airlines said it hasn’t given up on the plan.

Southwest, the airport’s top carrier, said last summer it would partner with ATA of Indianapolis to offer low-fare flights to Canada, Mexico and the Caribbean by 2009, and that BWI was among the airports under consideration to house the partnership.

Those plans were grounded last week when ATA filed for bankruptcy after it lost a major military charter contract and an agreement with FedEx was canceled early. But Southwest and BWI officials said the airline continues to negotiate with other potential partners.

“We are talking to other carriers now that ATA is out of service,” said Southwestern spokeswoman Brandy King, who declined to name specific airlines. “We are seeking other alliances.”

King said no specific airport had ever been announced to host the ATA-Southwest international service. BWI remained under consideration, she said, but chances of hosting the partnership, “would depend on the carrier we went with.”

BWI invested $147 million in its international terminal about 10 years ago, a facility that BWI spokesman Jonathan Dean said has generated more than $2 billion in economic impact for the region since its opening.

Four international carriers operate out of BWI: British Airways, Air Canada, Air Jamaica, and USA 3000. A fifth, North American Airlines, plans to cease flights from BWI next month.

Since 2001, when it served 924,645 international passengers, BWI has lost nearly a third of its traffic with just 625,039 international travelers passing through the airport, according to its own statistics. In that time, several international carriers have ceased operations at BWI, including Ghana Airways and Aer Lingus in 2004, Mexicana Airlines, and Icelandair last year. Last month, the small Air Greenland said it would halt flights out of BWI.

But none of those carriers individually represented a significant part of BWI’s international business, said Dean, and some, like North American, chose to cease scheduled flights altogether.

“BWI offers good international service,” he said. “Any U.S. airport that offers daily nonstop service to London Heathrow is in good shape. London Heathrow is the single most important international destination.”

acahall@baltimoreexaminer.com