Greece on Monday announced plans to sell 20% of shares in the National Bank of Greece (NBG) following the completion of the sale of a 9% stake in Alpha Bank to UniCredit as it looks to divest from the country's lenders.

The shares in NBG, Greece's second-largest bank by market value, will be sold via a public offering and a private placement from Nov. 14-16 at between 5 and 5.44 euros ($5.34-5.81) per share, the Hellenic Financial Stability Fund (HFSF) said in a statement.

The HFSF, a state-controlled bank bailout fund, acquired stakes in Greece's biggest lenders in return for injecting about 50 billion euros to recapitalize them during the country's financial crisis. It currently holds a 40.4% stake in NBG and a 27% stake in Piraeus Bank, Greece's third-largest lender.

NBG's shares were down about 1% at 5.39 euros at 10:12 a.m. GMT on Monday, with the 20% stake valued at about 1 billion euros.

"Out of the 20% holding, 17% will be offered to funds and 3% to retail investors. If there is strong demand, then HFSF might increase the stake to be offered to 22%," an official involved in the process told Reuters.

Earlier on Monday, HFSF said it sold its 9% stake in Alpha Bank to UniCredit for 293.5 million euros after an improved bid from the Italian bank.

Greece has been attracting significant investment as its economy strengthens after the crisis, prompting S&P Global to upgrade the country to investment grade in October.