BERLIN (Reuters) - German exports to Britain and the United States dropped sharply in the third quarter, data from the Federal Statistics Office obtained by Reuters showed on Friday, highlighting the impact of the Brexit vote and the U.S. presidential race on trade.

Exports to Britain, Germany's third-largest export market, were down 4.7 percent in the July-Sept period compared with last year, when they rose by some 11 percent in the third quarter.

Exports to the United States, Germany's biggest trading partner, fell by 10.5 percent year-on-year in the third quarter, the data showed. They also fell by 6.3 percent in the first nine months of this year.

Germany has been relying on private consumption and increased state spending for growth, which have replaced exports as the main economic engines.

For the whole of 2016 exports to the U.S. are expected to have fallen by 7 percent, said Germany's DIHK Chambers of Industry and Commerce. In 2015, exports to the U.S. rose 19 percent to total 114 billion euros.

"This is a real damper on our most important export market," DIHK economist Volker Treier told Reuters, blaming the subdued exports on the uncertainty created by the fierce presidential race between Democratic candidate Hillary Clinton and Republican Donald Trump, who won the election on Nov. 8.

"The uncertainty is very big, above all after the victory of Trump," Treier added. "His foreign economic program is not encouraging, as he has repeatedly spoken about imposing tariffs. This worries German exporters."

(Reporting by Rene Wagner and Michael Nienaber; Writing by Joseph Nasr; Editing by Caroline Copley and Toby Chopra)