MILAN, Jan 24 (Reuters) - Italian billionaire Francesco Gaetano Caltagirone has emerged as a leading player in the reshaping of Italy's financial sector that is currently under way.

BATTLES IN GENERALI AND MEDIOBANCA

Caltagirone last year expanded his investments in Italy's financial sector and is now a key shareholder in bailed-out bank Monte dei Paschi di Siena BMPS.MI (MPS) and fund manager Anima Holding ANIM.MI.

On Friday MPS launched a surprise 13.3 billion euro all-share offer to buy merchant bank Mediobanca MDBI.MI, in which over the last five years Caltagirone has become the second-biggest investor.

He is the third-largest shareholder in Italy's top insurer Generali GASI.MI, with a 6.9% stake. Mediobanca is the top investor in Generali with a 13% stake.

Caltagirone has repeatedly complained that Mediobanca exerts excessive influence on Generali through the board and a governance system which allows outgoing directors to name their successors.

As a long-standing investor and board member at Generali, in 2022 he and late fellow billionaire Leonardo Del Vecchio sought in vain to oust CEO Philippe Donnet.

Prime Minister Giorgia Meloni's conservative government has approved contested corporate governance changes championed by Caltagirone, and criticised by fund managers, which tighten the terms under which a company's outgoing board can file a list of successors.

Donnet's term comes up for renewal in the spring and he is expected to be put forward for another mandate backed by Mediobanca.

WHAT IS HIS ROLE IN ITALIAN BANKING CONSOLIDATION?

Caltagirone's holdings potentially pit him against UniCredit CRDI.MI CEO Andrea Orcel who in November launched a buyout offer for Banco BPM BAMI.MI, shortly after BPM had launched its own bid for Anima and bought a 5% stake in MPS.

The Treasury in Rome has long favoured combining BPM with MPS, which both partner with Anima, and building a core of long-term shareholders as it re-privatises the Siena-based bank it rescued in 2017, sources have said.

Before UniCredit upended Rome's plans, Caltagirone, with a 5% stake in MPS, a 5.3% Anima holding, and 2% of BPM, looked set to become a significant shareholder in the combined entity.

Caltagirone in December named two representatives to the MPS board, including his son Alessandro.

WHO IS CALTAGIRONE?

An Italian entrepreneur with interests in construction, the cement industry, real estate, publishing and finance, Caltagirone was born in Rome on March 2, 1943 to a family of Sicilian descent.

According to Forbes' 2024 wealth ranking, Caltagirone is Italy's 10th richest person with an estimated wealth of 5.6 billion euros ($5.9 billion).

He owns Rome-based daily Il Messaggero, Italy's eighth-largest newspaper by circulation, which is broadly supportive of Meloni's government, and several regional newspapers.

Despite his wealth and influence, Caltagirone keeps a relatively low profile and rarely gives media interviews.

He started out by reviving his late father's building business alongside his two brothers and a cousin. He expanded in the 1980s with the acquisition of Vianini Group, a Milan-listed cement and infrastructure firm.

His cement company Cementir CEMI.MI, listed on the Italian Stock Exchange, has a presence in 18 countries with 3,000 employees worldwide. It is the largest cement producer in Denmark, the third-largest in Belgium and among the main international grey cement operators in Turkey.

Caltagirone has three children - Francesco, Alessandro and Azzurra - all involved in his operations, but no designated successors.

($1 = 0.9529 euros)

(Reporting by Gianluca Semeraro; editing by Kirsten Donovan)

((gianluca.semeraro@tr.com; +39 06 80 307 741;))