* Euro rises on month-end position squaring
* Risk aversion slightly, but euro zone debt worries remain
* Euro still on course for 6th monthly fall in a row vs dlr
By Jessica Mortimer
LONDON, May 28 (Reuters) - The euro rose on Friday as investors unwound hefty short positions ahead of the month-end, while the recent extreme risk aversion stemming from euro zone debt concerns eased.
Traders said fixings related to position squaring before the end of the month dominated the session, with many trades brought forward due to Monday's U.S. and UK public holidays.
The euro gained more than 1.5 percent on Thursday after China reaffirmed its commitment to diversify currency holdings away from the dollar, easing concerns that the euro may be quickly losing favour as a reserve currency.
Thursday's Spanish parliament approval of a 15 billion euro austerity package also brought relief. However, analysts expected euro gains to be limited as investors stayed mindful of the severity of the euro zone's debt problems.
"There seem to be a lot of month-end fixings and the euro is gaining from these. No matter how bad things are, if the market's positioning is all one way then there's a bit of a need for a breather," a London-based trader said.
"But there is bound to be more bad news on the horizon, which will send the euro into another downward spiral."
The Spanish package was passed by one vote and investors were concerned about possible strike action by Spanish unions, as well as the risk of civil unrest in Greece. [ID:nSGE64Q00Q]
At 0958 GMT, the euro was up 0.3 percent at $1.2409 EUR=, having risen as high as $1.2452, with traders citing buying by a large European bank, though they also mentioned market talk of options barriers at $1.2500, which were capping gains.
Analysts said a key support level was $1.2135, the 50 percent Fibonacci retracement of the 2000-08 advance, just above the recent four-year low of $1.2143.
The euro EURJPY=R was up 0.4 percent at 113.12 yen, while it rose 0.4 percent against sterling EURJPY=R to 85.09 pence.
Data last week from the Commodity Futures Trading Commission showed speculators were heavily short euros to the tune of 107,143 contracts in the week to May 18, although slightly less than the record net short position the prior week. [IMM/FX]
TREND STILL DOWN
Analysts saw the euro's gains over the last two days -- which took it above $1.2400 from the week's low hit on Thursday of around $1.2152 -- as a temporary reprieve before concerns stemming from the euro zone crisis return to haunt the currency.
The euro is set for its sixth consecutive monthly fall against the dollar and has fallen close to 7 percent in May.
"Our underlying unease with the euro remains. This is one currency where the market continues to be terrified about what might be lingering around the next corner," Daragh Maher, currency strategist at Credit Agricole CIB said in a note.
Charts show a monthly close below $1.2135 would favour more weakness, with analysts seeing the next downside support at $1.1640, a trough hit in November 2005.
The dollar JPY= rose 0.1 percent to 91.17 yen, while the dollar index .DXY, which measures the greenback's performance against a basket of currencies, fell 0.15 percent to 86.048.
A large amount of options in dollar/yen is expected to expire during New York trading hours on Friday with a strike at 90.00, and that may provide near-term support to the dollar against the yen, a senior options manager at a European investment bank said in a note to clients.
(Additional reporting by Masayuki Kitano and Satomi Noguchi in TOKYO)