But this example points to some of the obstacles to Mr. Garnier’s proposal. The Treuhandanstalt was criticized for laying off nearly 2.5 million workers of the 4 million it had inherited and for closing businesses that critics said were profitable. It contributed to East-West resentment over the social and financial costs of unification, and its first president was assassinated by (West German) Marxists.

Privatizing state-owned companies and property are a key part of the bailout programs prescribed by the European Union and the International Monetary Fund for the euro zone’s debt-laden governments. Yet Greece’s consistent failure to meet its privatization revenue goals highlights just how hard it is to attract serious investors to countries mired in deep recession, and to sell even profitable businesses for a fair price.

An attempt by Athens to sell its natural gas company, Depa, collapsed in June, blowing a hole of €1 billion, or $1.3 billion, in its bailout plan, and raising further doubts about plans to hawk the state gambling monopoly and the money-losing railroad.

Elsewhere in the region, so-called vulture funds of private equity investors are looking to pick up stakes in blue-chip Spanish companies at knock-down prices after bailed-out banks were forced to divest.

With Mr. Garnier’s model, a long-term investment vehicle funded by both private sector savings and the German government, or with a state guarantee, would buy up the assets, taking them off their governments’ books, then restructure and run them until they could be sold off profitably.

The German economists Daniel Gros and Thomas Mayer suggested last year that Germany should create a sovereign wealth fund, like those of Norway, Singapore and Saudi Arabia, to invest excess savings. Such a fund would be a safer and more efficient way to place German savings than in unremunerated deposits, they argued, and would have the side benefit of lowering the euro’s exchange rate, which would benefit struggling south European economies.

Mr. Garnier would put that money to work inside the euro zone. He notes that Germany’s state-owned development bank, KfW, is already dipping a toe in these waters by providing loans through its Spanish counterpart to credit-starved small and medium-size businesses.