The operator of Narita airport announced Thursday that its terminal for budget airlines will double in size to address congestion by March 2022.

The expansion of Terminal 3 at the airport in Chiba Prefecture will raise capacity to 15 million passengers a year from 7.5 million, Narita International Airport Corp.(NAA) said.

"Low-cost carriers have captured more-than-expected demand . ... We want to contribute to the growth," NAA President Makoto Natsume told a news conference.

The expansion will involve Japan Airlines Co.'s cargo facility next door. JAL has broadly agreed to move the facility elsewhere, according to NAA and other sources.

Terminal 3, which opened in April 2015, comprises a three-story main building and a two-story satellite facility with total floor space of roughly 66,000 sq. meters. It is used by five budget airlines.

Low-cost carriers accounted for 30.7 percent of all passenger flights at Narita airport from Oct. 29, 2017, to March 24, up from 11.5 percent in the same period in 2013 and 2014, the operator said.