FOREX-Euro climbs vs dollar, lifted by Greece rescue talk

* Investors eye potential Greece rescue

* Weight of euro positioning seen forcing short squeeze

* Euro on pace for best day vs dollar since November

* Risk appetite improves, stocks rise (Adds quotes, updates prices)

By Gertrude Chavez-Dreyfuss

NEW YORK, Feb 9 (Reuters) - The euro firmed against the U.S. dollar on Tuesday, on track for its best one-day gain since November, boosted by reports of a possible bailout by European authorities of debt-strapped Greece.

Reuters reported that euro zone governments have decided in principle to help Greece, a member of the 16-member euro zone bloc. [ID:nBAT005104]

"If they do come and help Greece, (that) would do it for now. It would help bring the euro back from the multi-month lows," said Greg Salvaggio, senior vice president for capital markets at Tempus Consulting in Washington.

In midday New York trading, the euro was up 0.8 percent on the day at $1.3760.

The euro has fallen nearly 9 percent from a 15-month high of $1.5145 reached in late November over fears about fiscal problems in Greece, Portugal and Spain.

Speculation about Greece prompted a recovery in global equities, with U.S. stocks trading nearly 2 percent higher. [ID:nN09243041].

Analysts said the euro's rise also reflected the unwinding of what was seen as extreme positioning. The latest data from the Commodity Futures Trading Commission showed a record build-up of short euro positions, according to Barclays. [ID:nN05162244]

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In addition, the premium investors demand to hold Greek government bonds rather than euro zone benchmark German Bunds fell to its lowest since Jan. 27 on Tuesday, indicating some easing of Greek-related tensions. [ID:nLDE6181N1].

"I think it's mainly positioning. Bearish trades on the euro and those in favor of further spread widening are so heavy that people are just trying to reduce those bets, having made some profits," said Sebastien Galy, senior currency strategist at BNP Paribas in New York. "I think fundamentally nothing has changed."

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For a graphic on the euro and Greek bond spreads, click http://graphics.thomsonreuters.com/0210/EZ_EURGR0210.gif ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The euro was firmer versus the yen, with gains of about 1.0 percent at 123.21 yen . It fell to its lowest level in nearly a year on Friday as sentiment on the euro zone currency deteriorated further but picked up some lost ground on Monday.

A slight increase in risk appetite also fueled some reduction in yen longs established during last week's bout of risk reduction, with the dollar rising 0.2 percent to 89.55 yen.

The dollar held a softer tone versus a basket of currencies <.DXY>, however, trading down 0.6 percent at 79.847.

Sterling initially fell after ratings firm Fitch said Britain was among the most vulnerable of triple A sovereigns, but recovered with news about a possible Greek bail-out. The British pound was last at $1.5659 , up 0.4 percent on the day. (Additional reporting by Vivianne Rodrigues; Editing by Dan Grebler)