Euro zone officials have outlined three basic options for private sector involvement in the second bailout package for Greece in a teleconference on last week, a document prepared on July 16 showed.

The document, obtained by Reuters, said the first option was a buy-back of Greek debt and public sector credit enhancement. It would likely cause a downgrade of Greek debt to selective default or default by ratings agencies.

The second could be based on the French banks' proposal of a debt rollover, which does not involve public sector credit enhancement. It would likely trigger a downgrade to selective default, the paper said.

The third option could be based on a tax imposed on the financial sector or a decentralized Vienna-type agreement with private banks, especially Greek ones which have large holdings of Greek debt, to maintain exposure. This option was unlikely to result in a selective default rating, the paper said.

(Reporting by Luke Baker, writing by Jan Strupczewski, editing by Rex Merrifield)