Investors showed growing scepticism on Tuesday that euro zone finance ministers will thrash out an agreement soon to beef up a rescue fund as part of measures to end the region's sovereign debt crisis.

The ministers showed no indications they were closing in on any firm decisions on Monday. The chairman of euro zone finance ministers, Jean-Claude Juncker, said they discussed many options, but favored none.

In response, the euro fell broadly as hopes faded for an immediate agreement to increase the size of the bailout fund and the currency continued to slide in Asian trade on Tuesday.

Germany, the biggest euro zone economy that is key to any agreement on changes, has indicated no rush to take action especially since bond markets are calmer following successful debt auctions by Portugal and Spain.

What indications we have heard from European officials over the past several days is that they just don't feel the same sense of urgency that the market does, said Todd Elmer, currency strategist at Citi in Singapore. I think for the time being that means the euro is likely to trade lower.

The European Financial Stability Facility (EFSF) was set up in May 2010 to borrow money on markets with euro zone government guarantees of up to 440 billion euros.

But because it wants to have the top credit rating of triple A, the effective amount the fund can lend to countries in need is around 250 billion euros.

Both Greece and Ireland have been bailed out during the debt crisis and markets are worried that Portugal and possibly Spain could be next.

Markets want to see more money available for the fund because they estimate the current amount would not be sufficient if both Portugal and Spain applied for emergency financing.

Euro zone policymakers are expected eventually to increase the firepower of the EFSF by 260 billion euros to reach 700 billion, a Reuters poll shows.

Last week, the European Commission and the European Central Bank called not only for the EFSF to have more money but also to use it in a different way -- for example to buy government bonds on the secondary market, like the ECB does now.

Germany has so far opposed the idea and Juncker would not give any details on what support that idea had among euro zone finance ministers on Monday.

German Finance Minister Wolfgang Schaeuble said there was no need to increase the size of the rescue fund at this point.

Portugal doesn't want or need a bailout at all. There's enough funds for Ireland and the rest is speculation that is not being stirred up by anyone, he told German radio on Monday ahead of the finance ministers' talks.

Juncker vowed to accelerate work on the package, but was careful not to commit to being ready in time for the February 4 or March 24-25 European Union leaders' summits.

I wouldn't give a date for conclusion of our work, but the work will be done at the highest speed possible, Juncker said.

BELGIUM THE LATEST TEST

The euro fell as low as $1.3250 in Asian trade on Tuesday before finding some support and bouncing up to around $1.3315 at 10:30 p.m. EST.

Still, that was well below a one-month high of $1.3458 on Friday before the currency started to slide ahead of the euro zone talks.

U.S. Treasuries firmed in Asia, after a market holiday on Monday, drawing some support from waning hopes for a quick deal to bolster the rescue fund.

Belgium provides the latest test of investor sentiment over euro zone debt on Tuesday with an issue of three-month and 12-month treasury certificates.

The country was largely untouched by the euro zone's debt crisis until November, when contagion concerns grew.

The lack of a government for seven months is feeding market fears political paralysis will undermine efforts to cut a public sector debt that is almost as large as annual economic output.

Bolstering market sentiment, the ECB said on Monday it bought 2.3 billion euros in euro zone government bonds last week, its biggest weekly purchase for more than a month. The buying helped calm markets, enabling Spain and Portugal to stage successful auctions.

Madrid canceled another planned bond auction on Monday and decided instead on a 10-year bond sale through a syndicate of banks, to raise 6 billion euros.

(Reporting by euro zone bureaux; writing by Neil Fullick, Editing by Dean Yates)

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