A record 19.7 million passengers flew through Reagan National Airport in 2012, surpassing the previous record of 18.8 million set in 2011, according to a report to be presented to the board of the directors of the Metropolitan Washington Airports Authority at its meeting on Wednesday.

At Washington Dulles International Airport, which celebrated its 50th anniversary in 2012, 22.6 million passengers passed through — compared to 23.2 million the previous year, the report said. Officials at MWAA, which oversees both Dulles and Reagan National said the drop at Dulles was due in part to declines in domestic traffic.

As the entity responsible for overseeing operations at both Dulles and Reagan National, MWAA officials have had to manage the slowdown in passenger traffic at Dulles while also grappling with the long lines and testy customers that come with the huge growth in passenger traffic at Reagan National.

But officials remain optimistic that there is still huge potential for growth at Dulles.

Mark Treadaway, vice president for air service development at MWAA, said he sees potential in Latin America for more international flights. Adding that MWAA is “constantly looking for markets that are complimentary to our market.”

In 2012, Dulles added a host of international destinations to its offerings, including Porter Airlines to Toronto, Aeromexico Airline to Mexico City, and Emirates to Dubai.  In addition, United launched services to Doha, Manchester, Dublin and San Salvador. Copa Airlines expanded service to Panama.  Cayman Airways returned to Dulles with service to Grand Cayman. About one in four of Dulles’ passengers are international travelers.

While Reagan National has no room to expand, Dulles is surrounded by open land. Construction of the Silver Line, which will provide a rail link to the airport, will also help fuel the desire for more development, officials say.

Last year also proved to be a record breaker for another airport in the region, Baltimore-Washington International Marshall Airport, which posted record gains in passenger traffic for the third straight year. More than 22.6 million travelers flew through BWI Airport in 2012.