Euro zone leaders reached a deal in principle on Saturday on making the 440 billion euro ($611 billion) bailout fund more flexible, and also agreed other elements of a comprehensive package to resolve the debt crisis, two EU sources said.

A deal has been reached to make the EFSF more flexible, one diplomatic source said, referring to the European Financial Stability Facility, set up last year and used to bail out Ireland. Another confirmed that a deal had been struck.

There is also a deal on other parts of the comprehensive package, said the first source, although he said he couldn't provide details as elements were still being finalized.

He said technical experts were drafting a statement for the 17 euro zone leaders and they were expected to sign off on it shortly.