The announcement on Wednesday ends Chinese technology giant Huawei's efforts to enter that market segment in Portugal despite European concerns that Chinese involvement in critical infrastructure could compromise security.

Reuters has previously reported that Portugal's three main telecoms players - Altice, NOS and Vodafone - would not use Huawei's 5G network technology even though there is no official ban in Portugal.

Altice Portugal said it had established a strategic partnership with Nokia, which will be responsible for development of its standalone core 5G network including transition to a cloud-based network.

It said the standalone 5G core network will make it possible to deliver more innovative mobile services and "will also provide greater levels of security, using strengthened encryption algorithms for increased privacy".

The services to be delivered by the new high-performance 5G core network will guarantee nationwide coverage, aimed at meeting the critical communications needs of industries, public bodies, cities and companies, the company added.

Portugal's existing 5G networks are not standalone and are still largely based on 4G technology, with the exception of the antennas.

Altice Portugal said its current 5G network covers 90% of the population.

(Reporting by Sergio Goncalves; Editing by David Goodman)