BRUSSELS, Dec 18 (Reuters) - The euro zone's unadjusted trade surplus fell year-on-year in October as imports in the first 10 months of 2008 grew much faster than exports, due mainly to more expensive energy, data showed on Thursday.
The unadjusted surplus came to 900 million euros ($1.29 billion), down from 4.2 billion in October 2007 as imports for the month rose 3 percent year-on-year and exports only 1 percent, European Union statistics office Eurostat said.
Economists polled by Reuters, however, had expected a deficit of 4.5 billion euros.
In the first 10 months of 2008, imports grew by 10 percent against the same period of 2007 while exports rose 6 percent.
Detailed data for October was not yet available, but the trend was clear from the January-September numbers, which showed the energy trade deficit rising to 235.5 billion euros from 164.6 billion a year earlier.
Seasonally adjusted, the euro zone had a trade deficit in October of 1.3 billion euros, down from 4.4 billion in September as exports fell only 2.5 percent against the previous month while imports declined 4.6 percent.
The balance with the euro zone's top four trading partners -- Britain, the United States, China and Russia -- deteriorated in each case in January to September, the data showed.
With the economies of the two biggest -- Britain and the United States -- slowing sharply or in recession, euro zone exports are likely to face more pressure despite a recent fall in the euro exchange rate, economists said. (Reporting by Jan Strupczewski, editing by Dale Hudson)