Germany's major banks have agreed to take part in a new aid program for Greece by accepting longer maturities on some EUR2 billion in bonds that currently fall due in 2014, Finance Minister Wolfgang Schaeuble said Thursday.

Speaking to reporters alongside Deutsche Bank AG Chief Executive Josef Ackermann, Schaeuble said the agreement also covers an additional EUR1.2 billion in bonds set to mature in 2014 held by "bank banks," government vehicles set up during the global financial crisis to take troubled assets off the balance sheets of banks.

Overall, he said, German banks hold some EUR10 billion in Greek government bonds, but about 55% of them aren't due to mature until after 2020.

"The portion that will mature in 2014 is relatively limited," Schaeuble said. "In total we're talking about a sum of EUR3.2 billion," Schaeuble said.

Schaeuble said the agreement, based on a similar proposal put forward in France, would help euro-zone finance ministers determine the broad outlines of a new aid package for Greece. The so-called Eurogroup meets Sunday in Brussels.

Ackermann said he recognizes that banks and euro-zone governments need to cooperate on a "quantifiable, sustainable solution" to Greece's persistent debt woes.

"We are certain that Greece needs to be helped with further aid," he said. "Certainly the French plan was a basis," for the agreement reached Thursday, he added.

Under the French proposal, holders of maturing bonds would agree to reinvest half the proceeds in 30-year Greek bonds, with a base interest rate of 5.5% that would rise if Greece's economy grows, a person familiar with the proposal said. The ceiling interest rate would be 8%.

Greece received a EUR110 billion bailout from its euro-zone partners and the International Monetary Fund in 2010, the government's public finances remain in disarray and recent deficit projections and economic growth figures have both been worse than that program anticipated. The Greek parliament on Wednesday approved a broad slate of aggressive economic reforms that euro-zone leaders and the IMF had presented as a condition for a new aid program.

-By Patrick McGroarty, Dow Jones Newswires, +49 30 2888 4128;

patrick.mcgroarty@dowjones.com