* Euro rises vs dlr, Greek source details austerity plan
* Dlr slips across the board, hits weakest vs yen since Dec
* Planned Greek bond seen big test for euro
(Adds comment, details)
By Naomi Tajitsu
LONDON, March 3 (Reuters) - The euro rose against the dollar on Wednesday, hitting the day's high as a Greek government source cited details of fresh plans to tackle Greece's debt problems.
The euro <EUR=> rose roughly half a U.S. cent to around $1.3663 after a Greek government source told Reuters the Cabinet would take extra austerity measures totalling 4.8 billion euros, the upper end of market expectations.
The European Union had been demanding that Athens find a way to save an additional 4.8 billion euros in its budget. The austerity plan also includes cuts to public sector bonuses and arise in VAT. [ID:nATH005244]
The report pulled the euro away from a 9 1/2-month low hit on Tuesday, boosted by a rise in Greek government bond prices which narrowed the 10-year yield spread against German ones, but analysts cautioned against premature optimism about the plans.
"The measures are largely positive as they are at the upper end of speculation ... so the euro is seeing a slight rally," said Elsa Lignos, currency strategist at RBC.
But she added that it was too early to tell whether the plans were enough to convince Greece's European Union partners that it can service its 300 billion euro mountain of debt.
"We're waiting to hear what the European reaction is going to be to the measures ... Although on the face of it the measures are at the upper end of speculation we are still cautious."
The Greek government is slated to officially announce the plans on Wednesday, before Prime Minister George Papandreou meets German Chancellor Angela Merkel in Germany on Friday.
Greece's fiscal crisis has battered the euro in past months, driving it down nearly 10 percent against the dollar since December, as it highlighted weakness in some euro zone countries and raised questions about the bloc's stability.
By 1022 GMT, the euro was 0.2 percent higher on the day at $1.3625, trimming some earlier gains. On Tuesday, it fell as low as $1.3432, its weakest since mid-May 2009.
Against the yen, it was unchanged on the day at 120.85 yen, having pulled back from the day's low around 120.62 yen after the reports about the Greek austerity plans trickled out.
Still, ongoing concerns about Greece kept the euro near a one-year low of 119.60 yen hit last week.
Analysts said support for the euro from Greece's belt-tightening plan could be limited as Athens still faced the hurdle of attracting demand for a 10-year debt sale expected soon as the country clamours for funds to refinance its debts.
"The sale will be the big test for the euro," said Antje Praefcke, currency strategist at Commerzbank in Frankfurt.
U.S. JOBS DATA AWAITED
The dollar <JPY=> fell as low as 88.47 yen in Asian trade according to electronic trading platform EBS, hitting its weakest since December, before pulling back to around 88.73 in the European session.
The dollar slipped across the board as traders trimmed long positions in the U.S. currency, which last week had built up to their highest levels since September 2008.
Against a currency basket, the dollar <.DXY> was slightly lower on the day at 80.400.
Some analysts expected currencies to trade in fairly narrow ranges as few traders would be keen to take on excessively big positions in the U.S. currency before the U.S. non-farm payrolls report due on Friday.
Before that, investors awaited U.S. ADP employment report at 1315 GMT, which is forecast to show 20,000 jobs were lost in February versus a loss of 22,000 in January.
Some analysts said a weaker-than-expected reading may trigger selling in the dollar.
(Editing by Toby Chopra)