LISBON, July 26 (Reuters) - Portuguese retailer Jeronimo Martins on Wednesday posted a 36% increase in first-half net profit as high inflation boosted sales, especially in Poland where it operates discount stores, although it also dented margins.

The company reported a net profit of 356 million euros ($394 million) between January and June.

Consolidated sales rose 22% to 14.5 billion euros, driven by its market-leading Biedronka chain in Poland, where sales increased 24.5% to 10.3 billion euros.

The company said in a statement that while food inflation gradually declined in the second quarter, it was "still difficult to predict the inflation reduction for the second half".

It plans to keep investment in 2023 at last year's levels of around 1 billion euros to open 130-150 stores in Poland and remodel 350 others, add over 200 locations in Colombia, around 20 Hebe-brand stores in the Czech Republic and Slovakia, as well as 10 new Pingo Doce stores in Portugal in the full year.

Outlining the company's priorities, Chief Executive Pedro Soares dos Santos said Jeronimo Martins sought to be "the first choice of an increasingly fragile consumer, to grow sales, to reinforce efficiency, and to protect profitability".

While consolidated earnings before interest, taxes, depreciation and amortisation (EBITDA) grew 18% to 1.0 billion euros, the EBITDA margin, a key measure of profitability, fell to 6.9% from 7.2% a year earlier following price investments and cost inflation.

"We know that in uncertain times with intense pressure on real household disposal income, it is essential to continuously provide the best saving opportunities by strongly investing in price to guarantee that consumers choose our stores," he said. ($1 = 0.9025 euros) (Reporting by Andrei Khalip and Sergio Goncalves)