BERLIN (Reuters) -German exports rose in August due to strong demand particularly from the United States and the United Kingdom, official data showed on Wednesday, defying market expectations of a decline.

Exports rose by 1.3% in August compared with the previous month, data from the federal statistics office showed.

The result compared with a forecast 1.0% decrease in a Reuters poll.

"The second slight increase in exports in a row is a small glimmer of hope, but no reason to sound the all-clear," said Volker Treier, head of foreign trade at the German Chamber of Commerce DIHK.

He said the export economy is still under pressure due to the high costs for energy, taxes and personnel, but also excessive bureaucracy.

"Fundamental improvements are urgently needed in Germany as a business location if the German export engine is to pick up in the long term," Treier said.

The foreign trade surplus broadened to 22.5 billion euros ($24.69 billion) in August from 16.9 billion euros in July.

"This is a punchy gain in the surplus, but our estimates still suggest that the inflation-adjusted trade surplus in goods is on track for a decline in the third quarter due mainly to a big fall in July, weighing on GDP growth," said Claus Vistesen, chief eurozone economist at Pantheon Macroeconomics.

Germany's trade surplus jump was boosted mainly by a sharp fall in imports, which fell by 3.4% on the month.

On the other hand, exports to EU countries rose by 0.8% on the month and exports to third countries increased by 1.9%, the data showed.

Exports of goods to the U.S. were up 5.5% compared with July and exports to the U.K. rose by 5.7%.

(Reporting by Chiara Holzhaeuser in Gdansk and Maria Martinez in Berlin, Editing by Miranda Murray and Muralikumar Anantharaman)