ATHENS (Reuters) - The euro zone is ready to take action, including extending loan maturities, to ensure the sustainability of Greek debt and the involvement of the International Monetary Fund in a rescue program for Greece, a Greek official said on Friday. Euro zone finance ministers gave their approval on Friday to a new aid program worth up to 86 billion euros to pull Greece from the verge of financial meltdown and ensure it remains in the single currency bloc. "The Eurogroup meeting reaffirmed... that the finance ministers are ready to take action such as longer repayment periods to ensure the viability of the Greek loan program." "That way, the IMF will participate in the program, something the Eurogroup considers essential," the official said. (Reporting By Michele Kambas; editing by David Stamp)