Germany's financial sector Thursday reached a draft agreement with the German government on how private bond investors will participate in plans to extend a new aid package to Greece.

The agreement, which follows a French plan reached last weekend, comes in time for euro-zone finance ministers discuss the aid program at a meeting in Brussels Sunday.

German finance minister Wolfgang Schaeuble will make a statement at 1300 GMT about the talks.

One person familiar with the matter said Thursday that a draft agreement had been reached but that it was still open as to which maturities of Greek sovereign debt will be rolled over under the German plan.

A second person said the debt rolled over by German financial firms could be a low single-digit-billion euro amount for Greek debt maturing between now and 2014. If it involves debt maturing between now and 2020, the volume would be a mid-digit-billion euro amount. Both people said the plan could still change as negotiations with German banks and insurers continue. Earlier this week, a person familiar with the matter put the rollover figure at around EUR7 billion.

Deutsche Bank AG (DB) Chief Executive Josef Ackermann and Commerzbank AG (CBK.XE) CEO Martin Blessing told a conference in Berlin Thursday that the German plan had used the one proposed by France as a blueprint, but that it required adjustments for the German financial sector. Such adjustments include the amount of time Greek bonds will be extended for. It must also consider how rating agencies and accounting firms will react. German financial firms have demanded assurances that rating agencies and accounting firms won't consider the arrangement to be a default.

German banks hold more Greek sovereign debt than banks from any country outside Greece, but French banks have more overall exposure to Greece because two of them own Greek banks.

Under the proposal by French banks and insurers, the maturity of Greek bonds would be extended to give the highly indebted country more financial breathing space.

The main option in the French proposal would be for holders of bonds to agree to reinvest half the proceeds of Greek government bonds that mature in the next three years into new 30-year Greek sovereign debt, with a base interest rate of 5.5%, which would rise if the Greek economy grows. The ceiling interest rate would be 8%.

The French plan proposes that a further 20% would be set aside to buy top-rated zero-coupon bonds with a 30-year maturity aimed at guaranteeing the capital repayment.

The assets would be managed by a special-purpose vehicle, allowing investors to remove the Greek bonds from their balance sheets.

European governments want the broad outline of a proposal for euro-zone private-sector participation in a Greek rescue package to be provided to the region's finance ministers when they meet in Brussels Sunday.

A new rescue package was also conditional on the Greek parliament approving austerity measures proposed by the government. The Greek parliament passed the reforms Wednesday and will vote on new legislation for the measures Thursday. The progress of the austerity plan has come against a backdrop of major public protests and rioting against them in Greece.

Greece has EUR64 billion of bonds maturing by 2014. It will need more aid on top of the EUR110 billion program it received from its euro-zone partners and the International Monetary Fund to meet future commitments.

Belgian Finance Minister Didier Reynders Thursday noted that progress on talks between European governments and private sector creditors is pushing forward a plan to solve Greece's most urgent debt problems.

"We try in different capital cities to discuss with banks, insurance companies and pension funds to manage it on a voluntary basis," Reynders said in Paris. "We've seen some progress in the private sector."

Reynders also said that although it is possible that the Eurogroup meeting on Sunday won't iron out all the plan's details, it may give the go-ahead for the next tranche of Greek aid worth between EUR11 billion and EUR12 billion to be paid by mid-July.

European Central Bank President Jean-Claude Trichet Thursday said it is in "Greece's interest" and in the interest of all of its neighbors to find a solution to the country's debt crisis. "I hope we can conduct this debate in a more serious way than hitherto," he said.

He stressed that he is against any involvement of the private sector in a "debt action" for Greece that isn't purely voluntary. He said that adjustment for Greece "is the first priority," adding that privatization is important for the embattled Hellenic Republic.

ECB Governing Council Member Ewald Nowotny called the French proposal on private sector involvement "a very, very interesting step for some countries." However it is important that there be a common European solution, he said, adding that discussions were taking place. He also said it is important to implement the measures quickly, especially privatization.

-By Ulrike Dauer, Dow Jones Newswires; +49 69 29725 500; ulrike.dauer@dowjones.com

(Eyk Henning, Patrick McGroarty in Berlin, Gabriele Parussini in Paris, Nicole Lundeen in Vienna, Todd Buell and Nina Koeppen in Frankfurt contributed reporting.)