BRUSSELS, Sept 17 (Reuters) - The euro zone's trade surplus grew more than expected in July as exports contracted much less than imports year-on-year and rose from the previous month while imports fell, Eurostat data showed on Thursday.
The seasonally unadjusted trade surplus in the 16-country area totalled 12.6 billion euros ($18.6 billion), compared with a 3.5 billion euro deficit a year before as exports fell 19 percent year-on-year and imports plunged 30 percent.
Economists polled by Reuters had expected a trade surplus of 5.2 billion euros. Eurostat revised up the June surplus to 5.4 billion euros from 4.6 billion.
The European Union's statistics office said that adjusted for seasonal factors, the trade balance was 6.8 billion euros, up from 2.3 billion in June and 1.5 billion in May.
Seasonally adjusted exports grew by 4.1 percent in July against June, the second consecutive month of gains after June's 0.9 percent increase over May -- a sign of improvement in external demand for euro zone goods.
Seasonally adjusted imports, however, fell 0.3 percent against June after a 0.2 percent rise in June against May, pointing to continued weakness in domestic demand.
Detailed data for July was not yet available, but a breakdown for the January-June period showed the euro zone's trade deficit in energy was only two thirds of the gap a year earlier, thanks to a hefty fall in oil prices.
The euro zone's trade deficit with Russia, one of the main energy suppliers, almost halved to 12.3 billion euros in that period. (Reporting by Jan Strupczewski; Editing by Dale Hudson)