The Food Safety Commission said Monday that it approved easing restrictions on U.S. beef imports, boosting supply to retailers such as Yoshinoya Holdings Co., as concerns about mad cow disease receded.

Japan, the biggest buyer of American beef before an outbreak in 2003, can raise the age limit for cattle to 30 months from 20 months because the change won't increase human health risks, Susumu Kumagai, the commission chairman, said in Tokyo.

It is the first relaxation of the Japanese regulation imposed to safeguard against the brain-wasting disease since the government ended a two-year ban on U.S. beef in 2005.

The new rule will widen opportunities for shippers such as Tyson Foods Inc. and Cargill Inc. Beef, autos and insurance are sectors the U.S. asked Japan to reform before joining negotiations over the Trans-Pacific Partnership free-trade pact.

Japan bought 10 percent more beef from the U.S. in the first half of 2012 because of the strong yen and concerns about the safety of domestic meat due to the Fukushima nuclear disaster.

The U.S. was the largest exporter to Japan after Australia in 2003, supplying 267,583 metric tons, worth ¥128.5 billion, according to data from the agriculture ministry. Tyson, JBS SA, Cargill Inc. and National Beef Inc. are the biggest U.S. beef suppliers to Japan, the federation said.

In the first half of 2012, Japan purchased 56,887 tons of U.S. beef, rising 10 percent from a year earlier. Total imports amounted to 240,815 tons, of which 64 percent was from Australia.