* U.S. GDP, initial jobless claims data support Fed taper in September * Dollar rises vs yen as Syria tensions ease * Dollar downside seen as limited on speculator position * Emerging currency relief also seen supporting case for Fed tapering By Julie Haviv NEW YORK, Aug 29 (Reuters) - The dollar hit a two-week peak on Thursday, and was on track for its largest daily gain against the euro in more than four months after strong U.S. data emboldened the view that the Federal Reserve could next month begin winding down its stimulus program. Investors bought the greenback after data showed the U.S. economy accelerated sharply in the second quarter thanks to a surge in exports. U.S. GDP grew at a 2.5 percent annual rate in the April-June period, more than double the pace clocked in the prior three months. "This is a good report for those who expect the Fed to taper in September," said Vassili Serebriakov, currency strategist at BNP Paribas in New York. "One of the key concerns that the Fed has voiced recently has been the dichotomy between firm employment and soft GDP growth. This should ease some of those concerns," he said. Still, Serebriakov doubted that the reports would sway the minds of some market participants who believe the Fed will not begin to scale back its stimulus until later. BNP Paribas, for one, has long held the view that the Fed will start winding down its asset purchases in December, noting that the U.S. economy is not yet at the point that would justify a tapering, he added. Other data showed the number of Americans filing new claims for jobless benefits fell last week. The drop in unemployment benefits was a potential sign of faster hiring in August. Should the next U.S. nonfarm payrolls report - due for release on Sept. 6 - show strong gains, it will cement expectations the Fed will scale back its asset-buying plan at its next policy meeting next month. Bob Lynch, head of G10 FX strategy at HSBC in New York, said he is not sure whether or not the second-quarter GDP data will play a major role in the Fed's policy deliberations. "Much of the 'later this year' tapering guidance from Fed Chairman Bernanke and other Fed officials is predicated on an expected rebound in growth in the second half of this year," Lynch said. "So in that regard, the revised Q2 GDP data are more backward-looking and the upcoming growth numbers - and the Fed's expectations - should play the bigger role in the policy debate," he added. The dollar was last 0.7 percent higher against a basket of currencies at 82.018, after earlier hitting 82.067, its highest since Aug. 5. Against the safe-haven Japanese yen, the greenback traded up 0.7 percent at 98.34 yen. Hedge funds and other speculative players in the foreign exchange market have grown defensive on the dollar over the past month, but that bearish trend could be a risky bet with the dollar's downside looking increasingly limited. The euro, meanwhile, plunged 0.8 percent against the dollar to $1.3234, on pace for its worst daily performance since mid-April. It earlier touched a low of $1.3218, a two-week trough. Market sentiment was still cautious, but prospects of an imminent Western intervention looked set to be delayed until U.N. investigators report back. Some said reduced tension in emerging markets also supported the U.S. currency as it reinforced bets the Fed would crimp monetary stimulus soon. "A slight easing of the tensions in Syria and emerging markets, has helped the dollar," said Simon Derrick head of currency research at Bank of New York Mellon. "Over the last few weeks tensions in emerging markets were seen as keeping pressure on the Fed to delay tapering which is dollar negative. With emerging markets now doing a little better, the dollar is higher." Emerging markets, the first to be hit by outflows of funds as investors braced for an eventual end to the Fed's monetary stimulus, have experienced more turbulence as the Syria crisis makes investors even more risk-averse. While a debt auction in Italy was relatively successful, borrowing costs for a new five-year bond rose as investors remained wary about the coalition government's stability, which weighed on the euro. The euro's recent resilience is likely running out of steam, according to the options market.