Japan logged a bigger-than-expected trade deficit of 520.3 billion yen ($6.5 billion) in April as higher energy costs pushed up imports, the finance ministry said Wednesday.

The deficit was larger than a shortfall of 477.7 billion yen registered in April 2011, a month after Japan was hit by a huge earthquake and tsunami which battered the world's third-largest economy.

It was also bigger than the 470 billion yen deficit expected by economists.

Exports in April rose 7.9 percent from a year earlier to 5.57 trillion yen, boosted by shipments of automobiles and vehicle parts.

But imports rose 8.0 percent to 6.09 trillion yen as the amount spent on oil and gas rose.

Japan has switched off its nuclear reactors following last year's disaster -- which sparked the worst atomic crisis in a generation -- with the nation turning to pricey fossil fuel alternatives to make up the shortfall.

Analysts have said that high prices for liquefied natural gas and rising imports in a country beset by a rapidly ageing population and shrinking manufacturing sector would likely generate trade deficits throughout 2012.