Cellnex expects to boost its annual revenues by around 1.2 billion euros through the deal, under which it also plans a further investment of up to 1.4 billion euros on as many as 5,250 new sites.

Since listing in 2015, the Barcelona-based firm has grown rapidly, buying up assets which have retained their appeal for investors despite the coronavirus crisis, thanks to their steady cash flows.

It will pay 8.6 billion euros in cash and issue 1.4 billion euros in new shares which will give the ports-to-telecoms group a 5% stake in Cellnex.

The deal covers assets in Italy, Britain and Ireland, where Cellnex already operates, and marks its entry into Austria, Sweden and Denmark. It will leave Cellnex with 103,000 towers and telecommunications sites.

Rolling out next-generation 5G Internet in the coming years will require more masts to connect billions of devices in an "Internet of Things" which is likely to ensure continued investment in the sector.

(Reporting by Nathan Allen and Isla Binnie; Editing by Bernadette Baum)