Euro zone expects ECB support as it seeks closer union-EU presidency

* EU's Polish presidency warns treaty change won't calm markets quickly

* Signals that European Central Bank must act to buy euro zone time

By Jan Strupczewski and Robin Emmott

BRUSSELS, Nov 30 (Reuters) - European Union finance ministers expect the European Central Bank to step in forcefully to calm bond markets if EU leaders agree to move towards fiscal union at a summit on Dec, 9, the Polish EU presidency said on Wednesday.

France and Germany aim to propose major changes to the way euro zone countries run their public finances next Friday, with much closer fiscal integration and the right to sue those who break EU budget rules in the European Court of Justice.

The changes are likely to require a change of the EU treaty.

The European Commission has also proposed it should get the right to check if a euro zone country's budget draft is in line with EU guidelines before it is voted on in a national parliament, and demand changes if necessary.

While the scope of the changes that are to be proposed on Dec. 9 is unclear, EU officials are privately talking about a partial loss of fiscal sovereignty for euro zone countries in exchange for stability and future joint debt issuance.

Poland's Finance Minister Jacek Rostowski, whose country holds the rotating presidency, said the expected proposals would ensure that governments would not be tempted to seek bailouts, or weaken their commitment to reform and budget discipline.

"After those proposals are accepted, there should be action taken in an extremely forceful way to ensure stabilisation of the markets in the period that will follow after the council meeting (on Dec. 9)," Rostowski told a news conference after chairing a meeting of EU finance ministers in Brussels.

He did not refer directly to the European Central Bank, but euro zone officials see it as the only institution now that has enough resources to take on markets.

TIME TO CALM THE MARKETS

Investors have been demanding ever higher yields from euro zone countries for their bonds, sceptical about the single currency area's ability to reduce debt while at the same time sustaining decent economic growth rates.

Rostowski, whose country is not in the euro zone, said it would be extremely important to stabilise the markets quickly because the proposed changes to euro zone fiscal rules could not be become part of the treaty in the short term.

"There will be worries, they will take time ... so it is absolutely essential that we really ensure that markets are properly stabilised," he said. "I think that all, almost all ministers are aware (of this need)," he said.

Euro zone officials have privately talked about the issue and hope the ECB will buy time for the euro zone to get on with reforms and move toward a fiscal union.

Rostowski indicated that right now, ECB intervention was the only viable option left.

"My view is that this is not controversial and it's also my view that on its own, the treaty changes that are likely to be proposed ... are only sufficient in the medium to long run to achieve the stabilisation of markets," he said.