* Dollar rebounds to around 88 yen after falling below 87
* Aussie rises vs yen after mining tax diluted
* Euro holds gains after bear squeeze, before U.S. jobs data
By Charlotte Cooper
TOKYO, July 2 (Reuters) - The dollar was on the defensive against the euro on Friday, holding near five-week lows, after a big short squeeze in the single currency ahead of U.S. jobs data, while the yen lost ground as the squeeze spilled into Asian trade.
The dollar has fast lost favour this week, undermined by concerns about the strength of the U.S. economy, and it plunged on Thursday, hitting its lowest this year against the yen, as short-covering by euro bears unleashed a chain reaction.
The dollar index <.DXY>, a gauge of its performance against six other major currencies, hovered just above a two-month low after it shed 1.6 percent on Thursday.
The index was steady at 84.69, having broken through its 55-day moving average at around 85.
The greenback staggered up against the yen after hitting a seven-month low of 86.96 yen <JPY=> in the fray.
But it faced selling at 88 yen, with the market on alert for any comments from Japanese authorities which might signal concern about yen strength.
"This is broad-based dollar sales. It's not risk aversion -- rather dollar aversion," said Masafumi Yamamoto, chief FX strategist Japan at Barclays in Tokyo.
The Australian dollar <AUD=D4> initially rose versus the greenback and climbed against the low-yielding Japanese currency after Australia's government announced a watered-down version of a proposed mining tax, easing concerns it could hurt business investment and share prices. [
]U.S. JOBS DATA LOOMS
The U.S. Labor department releases its June employment report at 1230 GMT. Economists are forecasting a loss of 110,000 jobs in June compared with an increase of 431,00 jobs in May. [
].A negative surprise could weigh further on the dollar, after soft economic numbers in recent sessions sent investors worried about a double-dip recession into safe-haven U.S. Treasury bonds and pushed yields down.
Dealers said Japanese importer buying of the dollar ahead of the three-day weekend in the U.S. helped lift it 0.4 percent to 87.98 yen <JPY=>, but its drop through 87.95 yen on Thursday, when options triggers sent it down, meant it had broken below the 95-88 yen range held so far this year.
One dealer said more options triggers lay below 85 yen. The dollar fell to a 14-year low of 84.82 last November.
The euro made its big move against the dollar on Thursday, surging more than 2 percent to $1.2541 in its biggest one-day advance since mid-March last year, and on Friday it was holding around $1.2500 <EUR=>.
Concerns about euro zone debt, the banking sector and liquidity problems had led investors to short the euro and growth-linked currencies and pile into safe-haven currencies like the Swiss franc <CHF=> and the Japanese yen <JPY=> in recent sessions.
But some of those concerns eased after Spain successfully sold 3.5 billion euros of five-year bonds, prompting many to unwind those short positions. Thinning liquidity ahead of the long Independence Day weekend in the United States also exacerbated the moves.
"Market players are putting off euro selling on the back of funding concerns in Europe for now," said Shuichi Kanehira, head of forex spot trading at Mizuho Corporate Bank.
Traders said the euro/dollar was struggling to move higher ahead of the U.S. employment data.
Charts indicate the euro faces near-term resistance at $1.2570, a 38.2 percent retracement of its decline from $1.3692 in April to $1.1876 in early June. Resistance could also come in at its 55-day moving average around $1.2550.
It was steady at 1.3266 Swiss francs <EURCHF=R> after hitting a record low 1.3073 on Thursday, and its gains on Friday came instead against the yen, where it rose 0.2 percent to 109.92 yen.
The yen also slipped to the Australian and New Zealand dollars, with the Aussie up 0.2 percent at 74.30 yen <AUDJPY=R> and the kiwi gaining 0.6 percent to 60.78 yen <NZDJPY=R> as short-term speculators covered short positions.
By later in the Asian session the Aussie had given up early gains against the dollar made after the mining tax news, with traders saying activity had fallen away as the jobs data neared.
It slid 0.4 percent to $0.8443 <AUD=D4> after climbing as far as $0.8510.
Tony Morriss, a senior FX strategist at ANZ, said the tax news was positive for the Aussie particularly in the short run as it removed some uncertainty weighing on the currency.
"But we have to see how it holds up, given the U.S. payrolls coming up and a long weekend in the U.S.," Morriss said. (Additional reporting by Anirban Nag and Reuters FX analyst Krishna Kumar in Sydney and Rika Otsuka and Hideyuki Sano in Tokyo; Editing by Joseph Radford)