The euro zone's trade surplus with the rest of the world jumped year-on-year in July as exports surged 7%, new figures show. 

But imports increased by only 1% because of much cheaper imported energy, the latest European Union's statistics office data showed. 

Eurostat said the seasonally unadjusted trade surplus of the euro zone rose to €31.4 billion in July from €21.2 billion a year earlier. 

For the whole of the European Union of 28 countries, the unadjusted trade surplus was €12.9 billion in July compared to €1.2 billion the year before. 

The main difference was imported energy - in the first seven months of 2015, the value of imported energy such as gas and oil to the EU was €201.3 billion, while a year earlier, when prices were higher, the imports totalled €268.7 billion. 

EU imports from Russia - the main energy provider for Europe - plunged 26% in the months from January to July. 

The EU's exports to Russia - which imposed counter-sanctions on EU goods in reaction to the EU's sanctions over the war in Ukraine - tumbled 31% in the same period.