LISBON, July 29 (Reuters) - Portuguese paper pulp producer Altri said on Thursday its net profit rose almost five fold to 44.8 million euros ($53 million) in the first half of the year, boosted by price increases and a progressive recovery in global demand.

Sales increased 17.9% to 386.9 million euros after the company sold 595,000 tons of paper pulp, of which 96% were exported to markets outside Portugal.

The company said in a statement it took advantage of a progressive recovery in demand in most markets, accompanied by successive announcements of price increases.

Chief Executive Jose Pina said the company had a strong operational and financial performance, with quarterly and half-year production and sales records.

"The company demonstrated that it is prepared to face this challenge (the pandemic), with resilience, creativity and a focus on delivering results," he said.

Altri said the international PIX price for bleached hardwood kraft pulp rose to $865 a ton as of June from $680 at the end of 2020.

Core earnings or EBITDA increased around 73% to 108.8 million euros in the first half and its operating margin improved to 28.1% from 19.2% in the same period of 2020.

Although Altri sees "more stability" in pulp prices in the second half, there were "consistent signs of solid demand in Europe", it said.

($1 = 0.8419 euros) (Reporting by Sergio Goncalves Editing by David Holmes)