LISBON, July 5 (Reuters) - STC Group and telecoms tycoon Patrick Drahi have broken off exclusive talks for Drahi's Altice group to sell its Portuguese business to the Saudi telecoms company, online economic newspaper Eco reported on Friday.

The Eco report, citing two unnamed sources familiar with the talks, said STC had offered 8 billion euros ($8.66 billion) for Altice Portugal, but the last two weeks of discussions about the final price led to a breakdown in the negotiations.

An Altice Portugal spokesperson declined to comment. STC declined to comment.

Altice Portugal is the largest telecommunications player in the country, operating fixed-line, mobile and pay TV services, in addition to jointly owning a fibre network with Morgan Stanley's infrastructure business.

Drahi is looking to sell the Portuguese subsidiary to reduce the debt of his transatlantic Altice empire, which currently stands at around $60 billion, based on the company's latest financial results.

($1 = 0.9242 euros) (Reporting by Sergio Goncalves, additional reporting by Hadeel Al Sayegh in Dubai. Editing by David Latona and Jane Merriman)