United Parcel Service Inc., the world's largest package-shipping company, and other carriers won permission to increase air service between the U.S. and Japan under an agreement reached Thursday by the nations' governments.

United States passenger airlines, such as Northwest Airlines Corp. and Continental Airlines Inc., that sell tickets for one another's flights also may schedule more flights between the two nations, the U.S. Transportation Department said in a statement.

Delta Air Lines Inc. "applauds the U.S. and Japanese governments for reaching an agreement," Sametta Barnett, the carrier's director of government affairs, said in a statement. Delta will get "greater flexibility" to sell partners' services, she said.

The U.S. and Japan have been trying to loosen restrictions on flights for four years to expand trade between the nations. The agreement falls short of a so-called Open Skies arrangement, such as the one the U.S. and European Union reached this year, that eliminates all restrictions.