ROME, Jan 31 (Reuters) - Italy will ensure that employment levels are maintained when it sells a stake in postal service Poste Italiane, Economy Minister Giancarlo Giorgetti told lawmakers on Wednesday.

The Treasury plans to sell all or part of its 29.3% direct stake in Poste, while holding onto another 35% through state investor Cassa Depositi e Prestiti (CDP).

Giorgetti told the Chamber of Deputies the sale would be launched when market conditions are right, and the offer would include Italian savers, including Poste employees.

Reiterating that Rome plans to maintain public control in all major state-owned companies, he said the bylaws of Poste contain a clause that no one outside the Treasury or other state bodies can hold a stake of more than 5%.

Under criticism from the political opposition for selling part of a key public service, Giorgetti said the government was helping public finances at no risk.

"There is no fire sale, there is public control, with an approach that is modern and open to markets," he said.

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.

Italy plans to raise roughly 20 billion euros ($21.76 billion) from asset sales between 2024 and 2026 to keep in check the euro zone's second-largest debt burden in relation to gross domestic product (GDP).

Disposals have taken fresh prominence in Italy as the period of expansionary fiscal policy triggered by the COVID-19 pandemic is set to end next year, when the European Union adopts stricter budget rules under the reform of its Stability and Growth Pact.

($1 = 0.9192 euros) (Reporting by Giuseppe Fonte, editing by Gavin Jones)