Japan Airlines and Japan Air System may have to give up some of their arrival and departure slots at Haneda and other domestic airports to get their merger plan cleared under the Antimonopoly Law, a senior transport ministry official said Monday.

"I imagine the question of arrival and departure slots will become a focal point," Masato Obata, vice minister for land, infrastructure and transport, said at a news conference.

He was referring to calls by the Fair Trade Commission for the two airlines to review their merger plan.

On Friday, the FTC criticized the plan as anticompetitive, saying it would cut the number of major players in the domestic market to two from the current three and limit new entries in the aviation market to fewer slots.

"We will ask them to return unused arrival and departure slots if they merge," Obata said.

The slots might be reserved for new entries into the domestic flight market, he indicated.

JAL and JAS are expected to work out amendments to their merger plan to win FTC approval.

The plan calls for JAL and JAS to merge their operations into three group firms by the spring of 2004 under a holding company to be set up in October.