WRAPUP 3--EU says Greek budget plan achievable but risky

* Almunia says EU backs Greek fiscal measures

* Warns there are risks, monitoring will be tough

* Greek manufacturing slows, markets calmer

* Govt must sell drastic measures to recession-hit public

(Updates bond yield spreads, adds statistics report)

By Jan Strupczewski and Silvia Aloisi

BRUSSELS/ATHENS, Feb 1 (Reuters) - Greece's deficit-cutting plan is ambitious but achievable, the EU economic and monetary affairs commissioner said on Monday, warning however that Athens may have to take extra measures to shore up its finances.

The remarks by Joaquin Almunia came as a key economic indicator showed Greece's factory sector shrinking faster in January while major euro zone partners thrived -- a grim backdrop for a country desperate to fix its spiralling debt.

The European Commission is due to publish recommendations on Wednesday on Greece's austerity plan to slash a double-digit budget deficit and restore investor confidence after the country took a pounding in the markets for weeks.

Greece's financial problems have also sparked fears of a spill-over effect on other weak, heavily-indebted countries in the euro zone, and talk about a possible bailout by the EU -- although German's finance minister said on Monday Athens must correct its past mistakes itself. "What we are saying to the Greek authorities is: your stability programme has established ambitious targets and objectives and we fully endorse these ambitious objectives," Almunia said in comments exclusive to Reuters.

"We consider that the achievement of these objectives in the coming three years, before the end of 2012, is absolutely necessary. These objectives are achievable but they are surrounded by risks."

Almunia said the EU would thoroughly monitor Greece's progress, and would demand additional measures if needed.

"We will not accept slippages on the path to the targets," he said. "Every time we see slippages, because some risks materialise, we will ask for additional measures to correct these slippages."

Analysts say the socialist government must act quickly, while it still enjoys solid support from a public opinion willing to pay a price if the measures are seen as fair. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^