"If you look at CTIL it matches all the requirements as a target for Cellnex," CEO Tobias Martinez told analysts on a conference call after announcing the 4 billion euro (3 billion pounds) investment.

Asked whether his firm would look to buy a stake in TDF, as Spanish newspaper Expansion reported earlier this year, Martinez replied: "We cannot afford in parallel a project like TDF."

(Reporting by Andres Gonzalez, editing by Isla Binnie)