The merchandise trade surplus expanded 22.8 percent in December to 1.11 trillion yen from the previous year, the Finance Ministry said Thursday, citing growing exports led by cars and declining crude oil prices.

December exports rose 9.8 percent to a record 6.95 trillion yen from the prior year, helped by a 21.1 percent rise in automobile shipments mainly to the United States and a 19.1 percent increase in steel shipments largely to South Korea for automobile production, according to the ministry's preliminary data.

Imports in December rose 7.6 percent to 5.84 trillion yen on higher import costs of nonferrous metals, nonferrous ore and liquefied natural gas.