FOREX-Euro hits 3-week high vs dollar as Greece fears ease

* Euro gains for 2nd straight quarter versus dollar

* Dollar share of currency reserves drop in first quarter

* More euro gains expected on ECB rate-rise speculation (Updates prices, adds quotes and background, changes byline)

By Julie Haviv

NEW YORK, June 30 (Reuters) - The euro leaped to a three-week high against the U.S. dollar on Thursday and headed for a second quarterly gain as Greece passed crucial bills to avert immediate default and on expectations that euro-zone interest rates will rise again next week.

Greece approved detailed austerity and privatization bills on Thursday in a crucial vote to secure emergency international aid. But analysts said longer-term dangers still lurk with credit insurance markets pricing in an 80 percent chance of Greece defaulting within five years. See [ID:nL6E7HU0SS]

"While much uncertainty about the outlook for Greece remains, the euro should enjoy additional near-term gains on the notion that imminent default is likely to be avoided," said Omer Esiner, chief market analyst at Commonwealth Foreign Exchange in Washington.

Investors will now likely turn attention to talks on private-sector participation in a new Greek assistance program. German Finance Minister Wolfgang Schaeuble said he had reached agreement with German banks and he expected a euro-zone deal on Sunday, based on a French plan for a voluntary debt rollover. [ID:nB4E7HR01H]

This type of plan should give the euro additional gains, but doubts about Greece's ability to effectively implement additional austerity measures should keep the euro's upside limited, Esiner said.

Month-end flows supported the euro, helping propel it to a three-week high above $1.45. The euro hit a high of $1.45388 on trading platform EBS and last traded at $1.4514, up 0.6 percent for the day.

Traders cited offers from sovereign names ahead of a reported options barrier at $1.4550. Support is seen in the mid-$1.44 region.

The euro is on track for a 2.6 percent gain this quarter and an 8.5 percent gain in the first half of the year.

Meanwhile, the U.S. dollar's share of allocated currency reserves fell in the first quarter, while global central bank holdings surged to a record near $10 trillion. [ID:nN1E75T11M]

Steven Englander, global head of G10 strategy at CitiFX, a division of Citigroup in New York, said one take-away is that the reserve manager community as a whole did not have a uniform EUR buying bias.

"This is a big surprise, given how many anecdotal reports of reserve manager buying of EUR emerged in Q1," he said. "This adds to our skepticism that the EUR's gains are sustainable."

The euro rose 0.6 percent to 90.33 pence , having hit a 15-month high of 90.70 pence, the strongest level since March, 2010. It also jumped to a two-week high against the Swiss franc, rallying 1.4 percent to 1.2213 Swiss francs .

The dollar fell 0.2 percent to 80.58 yen , on track for a loss of 3 percent this quarter and a loss of 0.8 percent for the first half of this year.

The euro also found support after the European Central Bank signaled it would raise interest rates again next week as data showed inflation in June well above the bank's target. See [ID:nLDE75T0OM] (Additional reporting by Wanfeng Zhou, Steven C. Johnson and Gertrude Chavez-Dreyfuss; Editing by Jan Paschal)