ROME, Jan 25 (Reuters) - Italy approved a decree to sell a stake in postal service Poste Italiane, a statement from Prime Minister Giorgia Meloni's office said on Thursday.

The sale is part of government plans to raise roughly 20 billion euros ($21.67 billion) through asset sales between 2024 and 2026 to keep in check the euro zone's second-largest debt pile as a proportion of gross domestic product (GDP).

Under the plan, the economy ministry will sell a stake in Poste Italiane while maintaining public control, the statement added.

The Treasury has a 29.3% stake in the postal service. State lender Cassa Depositi e Prestiti (CDP) owns an additional 35%.

"The modalities of the divestment will tend to favour a widespread shareholder base and the stability of the ownership structure," the cabinet office said without giving further details.

Poste, which will present its new industrial plan in March, is a financial conglomerate that has expanded beyond its core business into payments, mobile phone services and energy supply, as well as insurance and investment products.

Factoring in proceeds from asset sales, Italy's debt is seen edging down by just 0.6 percentage point between 2023 and 2026, when it is targeted at 139.6% of GDP. ($1 = 0.9229 euro) (Reporting by Giuseppe Fonte; Editing by Chris Reese and Jonathan Oatis)