Exor in December agreed to buy a 43.78% controlling stake in GEDI, which publishes daily newspapers La Repubblica and La Stampa, from CIR at 0.46 euros per share, for 102.4 million euros ($110 million).

The Agnelli's holding company also pledged to bid for the publisher's remaining shares at the same price.

Exor, which is the controlling shareholder in Fiat Chrysler and Ferrari, also owns 43.4% of The Economist. It has said it plans to apply its media sector experience to help GEDI grow and accelerate a technological and structural transformation of the publisher.

Exor said on Thursday that as well as closing the share purchase from CIR through its Giano Holding vehicle, it had bought another 5.06% stake from the Perrone family's Mercurio.

It also agreed to buy a further 6.07% stake from SIA BLU and Giacaranda Caracciolo in a transaction which is due to close before the launch of the mandatory tender offer.

All purchases are at 0.46 euros per share, it added.

Including a 5.99% stake it already had, Exor is set to hold at least 60.9% of GEDI through Giano Holding, corresponding to 63.21% of voting rights, the investment firm said.

CIR and Mercurio have agreed to each buy stakes in Giano Holding, representing 5% of GEDI, once the mandatory tender offer is completed, Exor said.

GEDI shares were up 0.4% to 0.459 euros at 1417 GMT, while Exor was trading up 0.9% at 48.8 euros.

(Reporting by Giulio Piovaccari; Editing by Alexander Smith)