A Tokyo taxi firm that caters chiefly to foreign businesspeople is suing to have a government decision rescinded that banned it from expanding its fleet, and thus offer services to airports, saying the state screening procedure lacks a legal basis.

According to the lawsuit, filed Wednesday, Royal Limousine, which employs multilingual drivers, applied for permission to increase its fleet to 80 cars from 50 last June to serve Tokyo's 23 wards and the cities of Musashino and Mitaka.

The Land, Infrastructure, Transport and Tourism Ministry's Tokyo branch rejected the application in November, saying it was not clear if the revenue projected from an expanded fleet would be derived from new demand, meaning the application doesn't meet screening requirements.

The ministry's Kanto District Transport Bureau said: "We cannot make any comment because we have not received information about the lawsuit."

Royal Limousine, which entered the taxi business in 2008, said the state screening standards are interfering with free enterprise.

"Screening standards are regulations for striking a balance between demand and supply, which have no basis in legal provisions. They are tantamount to a ban on fleet expansions and are illegal."

At a news conference, Royal Limousine President Kensaku Kaneko said the rejection of the application didn't make economic sense.

"We have been declining requests for services to transport clients to and from airports because of a limited fleet. It is strange that a company providing quality services is denied a chance to grow," Kaneko said.