* Euro/dollar sets 2-1/2-year high; gains vs GBP, JPY more modest

* Risk averse mood helps lift yen, Swiss franc

* Dollar index hits lowest since Jan 2015 as US yields drop

* Aussie hits highest since May 2015, kiwi up more than 1 pct (Adds details and quotes, updates prices)

By Shinichi Saoshiro

TOKYO, Sept 8 (Reuters) - The euro reached a 2-1/2-year high versus the dollar on Friday, as a policy meeting by the European Central Bank gave bulls cause for short-term optimism and did little to support the beleaguered U.S. currency.

Asked when the central bank will decide on potential policy tapering, ECB President Mario Draghi said on Thursday the bulk of these decisions will probably be taken in October. That was enough to make euro bulls upbeat on the single currency's near-term outlook.

But Draghi also said the ECB must take into account the weakening of inflation owing to the strong euro, with the central bank having opted to lower some of its inflation projections to reflect a firming common currency.

Furthermore, the ECB reaffirmed its ultra-easy policy stance by retaining rates at record lows, even keeping the door open to increasing bond purchases if needed, despite the euro zone's best economic run since the global financial crisis.

"A large part of the euro's gains is being driven by expectations towards ECB tapering. The market did not get the confirmation it expected regarding tapering, but it remains far from disappointed," said Bart Wakabayashi, branch manager for State Street Bank and Trust in Tokyo.

"If euro strength is to continue, this may actually prompt the ECB to refrain from tapering. But as demonstrated time and time again, the market tends to get ahead of itself."

The euro was up 0.4 percent at $1.2069 after touching $1.2090, its highest since January 2015. It has gained 1.7 percent on the week.

Junichi Ishikawa, senior FX strategist at IG Securities in Tokyo, said the euro "was bought on mention of tapering possibly starting in October. But the ECB sounded rather dovish overall and the euro probably should have been sold in response, particularly with German bund yields having fallen."

"But the euro still managed to gain, thanks to the dollar's underlying weakness," he said. "The dollar is under pressure from many fronts ranging from sluggish inflation, Trump risk and geopolitical concerns."

Against the yen and sterling, the euro's gains were more modest. It was a shade higher at 130.570 yen after rising 0.2 percent overnight.

The euro was up 0.25 percent at 92.00 pence, putting it about 0.4 percent stronger for the week.