Through the acquistion, worth 542 million euros ($638 million), GIC would raise its stake in Cellnex to 8.07% from a previous 5.57%, according to Refinitiv data.

Edizione, Cellnex's largest shareholder with a 13.02% stake, said it also agreed to sell an additional 0.98% stake in Cellnex to other three unnamed investors.

The transactions were unveiled as Cellnex prepares a 7 billion euro capital increase to fund an acquisition in France.

The Benetton family has said it would not participate in the capital increase.

Since its listing in 2015, the Barcelona-based firm, which has a market capitalisation of 21.6 billion euros, has grown rapidly to become Europe's largest mobile phone towers operator by buying up assets which have retained their appeal for investors thanks to their steady cash flows.

In its latest major deal, Cellnex reached an agreement with Altice and Starlight Holdco to acquire Hivory, which has around 10,500 masts in France, planning an initial investment of 5.2 billion euros.

($1 = 0.8493 euros)

(Reporting by Inti Landauro; Editing by Edmund Blair)