The plans will be in place from December 2014 and will run for 25 years. The partnership is designed to enable both companies to offer high-speed data access to an additional 450,000 homes and businesses throughout the country.
Vodafone Portugal has a unified communication strategy and its fibre-to-the-home (FTTH) deployment programme is designed to reach 1.5 million homes by mid-2015.
"This fibre sharing agreement is significant as it accelerates our fibre-to-the-home roll-out plans and enables us to bring converged products and services to almost half a million more homes and businesses across Portugal," said Philipp Humm, CEO of Vodafone Europe.
Portugal Telecom will provide Vodafone with faster time-to-market benefits, and give the company access to faster high-speed broadband, fixed telephony and television services, with the aim of increasing its reach to almost two million homes by the end of next year.
Both companies will maintain complete autonomy and flexibility in designing their retail offers under the agreements.
This agreement in Portugal follows an increasing trend across the world of operators sharing fibre network access as a way to reduce costs.