LISBON, July 27 (Reuters) - Portuguese pulp and paper producer Navigator said on Tuesday its net profit more than tripled in the second quarter from a year ago as the easing of COVID-19 restrictions in many countries led to a strong increase in sales.

Navigator said net profit rose to 40.9 million euros ($48.4 million) between April and June 2021, from 13.4 million euros a year ago, when Portugal and most of its export destinations were under severe restrictions to control the pandemic.

Navigator said sales increased 29% to 373.9 million euros, driven by "a recovery in paper volumes and an improvement in pulp prices".

The company sells more than 80% of its products to 130 countries on five continents and the rest to domestic clients.

"After a first quarter marked by new waves of COVID-19 contagion and lockdown periods in most of the group's key markets, the last three months have seen a progressive reopening of economies and a recovery in demand of paper," it said.

Navigator said it had "good prospects" for the second half of the year due to the "expected economic recovery combined with an improvement in the balance between supply and demand in the U.S. and Europe".

Its EBITDA - earnings before interest, taxes, depreciation and amortisation - increased 55% to 79.9 million euros in the second quarter and its operating margin grew to 21.4% from 20.7% in the previous quarter and 17.8% in the same quarter of 2020.

Navigator said it had cut its net debt to 658 million euros from around 700 million euros a year ago.

($1 = 0.8455 euros) (Reporting by Sergio Goncalves Editing by Catarina Demony and Mark Potter)