Although most of the international air travel in the Washington region flows through Dulles Airport, Baltimore-Washington International Marshall Airport is gaining in the market.

International air travel at BWI grew nearly 20 percent last year, and the number of international passengers using the airport has nearly doubled over the past five years.

“The Washington-Baltimore market is a very huge international market,” said Paul J. Wiedefeld, chief executive for BWI Marshall. “International [travel], obviously, is a lot of where the growth is.”

BWI enjoyed its second busiest year in passenger traffic last year with 22.5 million passengers, slightly off from the 22.7 million passengers in 2012, which was a record year. Reagan National Airport had its third record-breaking year in a row with 20.4 million passengers. Washington Dulles International Airport saw its overall passenger traffic decline to 21.9 million, down 2.7 percent from 2012, even though international passenger traffic hit a record high. Seven million passengers at Dulles traveled abroad in 2012, an increase of 4.6 percent from 2012.

BWI is looking to capture even more of the international air travel market. Southwest Airlines, the top airline at the airport, recently announced it was beginning flights from BWI to Aruba, Montego Bay and Nassau in July. Vacation Express will begin service to Grand Bahamas Island in May, joining the four international carriers at the airport: Air Canada, Southwest, British Airways and Condor.

German airline Condor offers nonstop service between BWI and Frankfurt twice weekly during the summer.

According to Wiedefeld, British Airways, which offers daily service to London Heathrow Airport, and Air Canada saw year-over-year growth at BWI last year.

“We announced during the summer the construction of what we call the D/E Connector, which comprises two additional international gates,” Wiedefeld said. “We’re doing that obviously in preparation for additional international growth.”

He said that growth could come from both existing airlines adding new routes and new airlines joining the airport.

“We are dealing with some other airlines and we’ll see what occurs,” he said.