TOKYO -- Due mainly to heavier fuel import bills, Japan logged its worst ever trade deficit for January, official data showed Wednesday.

Finance ministry figures showed the economy suffered a shortfall of 1.63 trillion yen (US$17.4 billion), the worst deficit on record for the month. Comparable data began in 1979.

Economists had expected an average shortfall of 1.3 trillion yen.

Exports increased 6.4% to 4.8 trillion yen, posting the first rise in eight months on higher shipments of automobile parts and other items.

But imports rose 7.3% to 6.43 trillion yen as imports of petroleum products, natural liquefied gas and crude oil soared.

Japan's fuel imports have risen since the 2011 earthquake and tsunami disaster sparked the world's worst nuclear accident in a generation, sending most atomic power plants offline.

Copyright Agence France-Presse, 2013