ROME (Reuters) - Economist Riccardo Barbieri is the new director general of the Treasury, replacing Alessandro Rivera.

The decision marks a victory for Prime Minister Giorgia Meloni, who has been lobbying to remove Rivera and is ready to play a major role in other future senior appointments, according to political sources.

Barbieri, 64, is currently the chief economist at the Treasury. He previously worked for JP Morgan, Morgan Stanley and Bank of America-Merrill Lynch.

"A cosmopolitan, Barbieri is one of the senior Treasury representatives who relates most frequently with Brussels," commented Francesco Galietti, founder of the political risk observatory Policy Sonar.

The ministry also proposed the confirmation of Biagio Mazzotta as state accountant general.

The director general of the Treasury plays a key role in overseeing state-owned companies and is the Economy Minister's Deputy in G7, G20 and IMF meetings.

The department he heads also manages the second-highest public debt in the euro zone, amounting to about 150 percent of GDP.

Those who have held the post include former ECB President and Prime Minister Mario Draghi, as well as Domenico Siniscalco and Vittorio Grilli, both former ministers of the Economy.

Meloni had targeted Rivera for the way he handled some dossiers such as Mps, controlled by the state with a 64 percent stake following a bailout in 2017 that cost taxpayers 5.4 billion.

In the end-of-year press conference Meloni had said that Mps had been "managed quite badly so far," a comment in which many saw an indirect criticism of Rivera.

In the coming weeks Meloni will have to handle other major appointments, as the boards of all major state-owned companies, starting with Eni and Enel, expire.

(Giuseppe Fonte, editing Claudia Cristoferi)