The European Central Bank is almost certain to reinstate Greek banks' access to its cheap funding operations next week, two sources familiar with the situation said.

This would allow Greek lenders to come off an expensive emergency lifeline after more than a year. 

Greek banks lost their access to the ECB's cheap funding mechanism early last year when Athens came to the brink of being ejected from the euro zone. 

Regaining the funding would be a big step in normalising an economy still weighed down by capital controls and adjustments related to its bailout. 

While Greece's debt is rated "junk" by credit agencies, the ECB is very likely to waive its investment-grade credit rating requirement at its June 22 Governing Council meeting.

This is provided that the next €7.5 billion tranche of bailout funds is disbursed on schedule early next week, the sources, who asked not to be named, said. 

The ESM euro zone bailout fund is scheduled to agree today to disburse the next tranche of loans and the money is set to be paid early next week, EU officials said earlier this week.

The waiver would also be the first step to including Greece in the ECB's asset purchase programme, though that will require further deliberations and may not happen until September, one of the sources added. 

Including Greece in the ECB's €1.74 trillion asset purchase programme will be discussed after Greece makes a debt payment to the ECB due in late July and once the ECB completes a debt sustainability assessment. 

The ECB discussed reinstating the waiver at its June 2 meeting but said further progress was needed before it could decide. 

The waiver does not automatically solve Greek bank's funding problems as they will still have limited eligible collateral so they can only switch a minor part of their €64.8 billion worth of Emergency Liquidity Assistance to the ECB's regular funding operations. 

Including Greece in the asset purchases would also be just a small boost for the country, as the ECB could only buy small amounts, less than €3 billion now, given various eligibility requirements.