International banks and insurers attempted to paper over major cracks in a proposed Greek debt rollover on Friday, saying there was broad support to reinvest in the country.

A show of unity in the form of a statement from the Institute of International Finance (IIF) lobby group came ahead of weekend talks among euro zone finance ministers and fears the private sector will fall short of the 30 billion euro target for them to contribute to the bailout effort.

A small number of options were being discussed, the IIF said, with the aim of providing substantial cash-flow support to Greece and lay the basis for a more sustainable debt position.

The private financial community is ready to engage in a voluntary, cooperative, transparent and broad-based effort to support Greece, the IIF said in a statement.

Options include a roll-over or extension of bonds that mature and the re-investment of creditor claims into long-dated instruments. It was also important to consider debt buyback proposals to reduce long-term debt, the IIF said.

France has put forward a plan whereby bondholders would reinvest at least 70 percent of the proceeds from bonds maturing between now and the end of 2014 into new 30-year Greek debt. The plan is being fine-tuned, but there is substantial work that needs to be done, several sources said.

Banks and insurers may fall short of the target of raising 30 billion euros from the plan if Germany's proposed 2 billion euro private sector contribution is a gauge.

There will be certainly a number of banks in the euro zone that won't participate as they don't find the model attractive, a person close to a big German bank said.

An alternative option is to include Greek bonds with maturities beyond 2014, a banking source said. German banks last week discussed including bonds maturing by 2020.

There are 82.6 billion euros of Greek government bonds maturing before the end of 2014, according to Reuters data. The European Central Bank and other euro area central banks hold an estimated 25 billion euros of that debt, leaving about 58 billion in private hands.

The French expect 80 percent of bondholders to participate in its plan. That would equate to a rollover of 46.4 billion euros of bonds, and 70 percent of that would provide 32.5 billion euros for Greek coffers.

But investors may prefer to redeem their bonds at maturity at par.

We suspect investors would rather take the cash ... It is still not clear why non-bank investors will participate, unless the EU is prepared to include a substantial degree of coercion, which would risk triggering the (credit event on) CDS, analysts at CreditSights said in a note.

The IIF is playing an informal role coordinating international banks to reach consensus about private-sector involvement in a bailout of debt-ridden Greece.

The group, representing over 400 financial firms, was created in 1983 in response to the international debt crisis and aims to help stabilize the industry, including managing sovereign risk.

Among those supporting its Greek statement were BNP Paribas , Deutsche Bank , HSBC , ING , Societe Generale , Commerzbank and insurers AXA and Allianz , a person familiar with the matter said.

French banks, the most exposed to the Greek debt crisis, reached an outline agreement to roll over holdings of maturing Greek bonds this week.

German banks and insurers on Thursday agreed to roll over their Greek bonds, but their 3.2 billion euro contribution includes 1.2 billion held by two state-backed bad banks.

German lawmakers said Berlin had failed to deliver on its promise of a substantial private sector role, and banks had gotten off lightly.

The insurance industry's contribution to the scheme will depend on whether it can resolve lingering uncertainties about the new 30-year bonds it would be required to hold.

We need long-term debt, so in principle a rollover of short-term credit into long-term credit is not a bad idea for an insurer, said one financial source familiar with the discussions.

Insurers were seeking to make sure the rollover plan did not treat banks more favorably than other financial firms or favor institutions from one country, a second insurance industry source said.

(Additional reporting by Douwe Miedema, Myles Neligan, Ben Deighton and Jonathan Gould; editing by Sophie Walker and Will Waterman)

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