Greece handed 18 billion euros ($22.6 billion) to its four biggest banks on Monday, an official said, allowing the stricken lenders to regain access to European Central Bank funding.

The long-awaited injection - via bonds from the European Financial Stability Facility rescue fund - will boost the nearly depleted capital base of National Bank, Alpha , Eurobank and Piraeus Bank.

"The funds have been disbursed," an official at the Hellenic Financial Stability Facility, who declined to be named, told Reuters.

The HFSF was set up to funnel funds from Greece's bailout programme to recapitalise its tottering banks. The HFSF allocated 6.9 billion euros to National Bank, 1.9 billion to Alpha, 4.2 billion to Eurobank and 5 billion to Piraeus.

All four are scheduled to report first-quarter earnings this week. [Reuters]