By Peter Laca BRATISLAVA, Dec 7 (Reuters) - The Slovak economy grew by a record 9.8 percent in the third quarter, data showed on Thursday, and analysts said the fast expansion may bring another interest rate hike in the coming months. The GDP figure confirmed a flash estimate released by the Statistics Office last month. The Office also said it had revised its full-year GDP growth forecast to 7.7 percent, from previously expected 6.5 percent. "The key drivers were investments, shown in inventories, and domestic demand," said Slovenska Sporitelna senior economist Maria Valachyova. "Inventories will transform into exports, and growth should remain strong in the future." Slovakia has had the highest growth rates among the four largest new EU members from central Europe over the past few years, and the third quarter figure brought it to the ranks of the world's fastest growing economies. Growth has been helped by rising household consumption after years of belt-tightening reforms. Investments have also increased, mainly thanks to large projects such as the car factories of French PSA Peugeot <PEUP.PA> and South Korean Kia Motors <000270.KS>, which will boost exports next year. "The growth structure suggests the increasing potential of the economy, rather than its overheating," said ING Bank senior economist Lucia Steklacova. The Slovak central bank will have a tricky task in weighing conflicting rate policy signals such as fast economic growth and slowing inflation. The bank has raised the key two-week repo rate by 175 basis points this year because inflation risks from high energy prices and economic growth could endanger the goal of adopting the euro in 2009. But a crown <EURSKK=> rise by 5.7 percent in the past three months has limited shop price growth and allowed the central bank to keep rates on hold for the second month in a row in November. The crown firmed slightly after the GDP data, to 35.445 to the euro, matching its all-time highs, from 35.465. Analysts said the GDP data did not point to an immediate need to raise interest rates further, but more monetary policy tightening may be needed in the coming months. "A slight acceleration in household consumption may mean the central bank will maintain a cautious monetary policy approach. We still maintain our prediction of a 25 basis point rate increase in the near term, depending on the crown exchange rate moves," Slovenska Sporitelna's Valachyova said. ((Reporting by Peter Laca; editing by Ruth Pitchford; Reuters Messaging: peter.laca.reuters.com@reuters.net; +421 2 5341 8402)) Keywords: SLOVAKIA ECONOMY/GROWTH