By Jan Strupczewski

BRUSSELS (Reuters) - The International Monetary Fund called on Thursday for the creation of a fund to help finance structural reforms in the euro zone, echoing ideas floated by the European Commission in 2012 but subsequently dropped in the face of German opposition.

IMF Managing Director Christine Lagarde said however, the central pool of money for the benefit of the euro zone could only be made available to countries that respect the EU's budget rules laid out in the Stability and Growth Pact (SGP).

"My idea is that in exchange for complying with the Stability and Growth Pact, for complying with commitments on structural reform, in return for that, countries would be pooling budgetary resources in a common pot which could be used for projects and certain operations," Lagarde said.

Structural reforms are key to boosting the euro zone's growth rates and making its economies more resilient to shocks, she said.

She said the common pot of money could be used in a similar way as the cash of the European Fund for Strategic Investments, which uses a relatively small amount of EU money to attract 15 times more from private funds to finance concrete investments.

The new, centrally financed initiatives could "help offset upfront net costs of structural reforms," the IMF said in a report on the economy of the 19 countries sharing the euro.

Speaking after talks with euro zone finance ministers, Lagarde told a news conference the new fund could pay for projects related to migration, refugees, security, energy and climate change.

The idea of a euro zone budget was first floated in November 2012 by the European Commission in a report on how to complete the Economic and Monetary Union.

The Commission said at the time that "a dedicated fiscal capacity for the Euro Area should rely on its own resources and provide sufficient support for important structural reforms in large economies under stress."

But the idea was dropped in later reports on the future of the euro zone, prepared by several EU institutions, because Germany and its allies believed it would be wrong to provide financial incentives to countries for reforms they had to do anyway for their own good or were obliged to by EU law.

Germany, Estonia and Luxembourg are the only EU countries that have posted budget surpluses since 2014.

Lagarde said the pooling of budgetary resources could put these surpluses to good use.

"That really calls on those that can make those surpluses available to others to actually do so," she said. "The IMF just said what it thought about how Germany could use its fiscal space which we continue to believe it has, so we gave a few ideas of our own," she said.

(Editing by Hugh Lawson)