The regulator ANACOM has reserved a spectrum in the 900 MHz and 1,800 Mhz bands for new entrants - part of what it says is push to encourage competition and improve services.

Overall Portugal is hoping to raise at least 238 million euros through the auctions that were delayed from early 2020 by the pandemic and are now expected to last into January, with licenses handed out in the first quarter.

Under the rules, long-time market players Altice, Vodafone and NOS will have to share their infrastructure and offer national roaming to the new entrants' customers, ANACOM said.

Established operators will have to commit to setting up 5G services covering 75% of the population by 2023 and 95% by 2025 - while new entrants will only have to cover 25% of the population by 2023 and 50% by 2025, the regulator added.

Although ANACOM dropped its proposed 25% discount for new entrants and made some adjustments, NOS said that did not remove "unprecedented discrimination" against current players.

"It is important to underline that these rules remain illegal. We will react with all vehemence before the courts and the European Commission, questioning and challenging the rules," NOS said in a statement sent to Reuters.

Vodafone, which said it had invested 1.6 billion euros in Portugal over the last six years, said "established operators are strongly penalized for their high investments". It also promised to contest the "unacceptable" rules in court.

A spokeswoman for Altice, whose chief executive has been critical of ANACOM's plans, said it was still analysing the rules.

Several spectrum lots will be auctioned in 700 MHz, 900 MHz, 1800 MHz, 2.1 GHz, 2.6 GHz and 3.6 GHz bands.

(By Sergio Goncalves; editing by Andrei Khalip and Andrew Heavens)

By Sergio Goncalves