Grupa Muszkieterów, the Polish arm of France's Les Mousquetaires, reported an 11.5% year-on-year growth in turnover to PLN 4.2 billion (€920 million) in the first six months of its financial year.
Sales in like-for-like stores increased by over 9.5% compared to the same period in the previous year.
Marc Dherment, general director of Grupa Muszkieterów in Poland, stated, "Such solid results confirm the strong business foundations of both networks managed by the group - Intermarché and Bricomarché.
"However, we approach them with caution, bearing in mind that since last March our base has been heavily burdened by the COVID-19 pandemic, the effects of which, although to a lesser extent, are still being felt."
Elsewhere, the company's Portuguese operations recorded sales of €2.2 billion in 2020, down marginally from €2.3 billion in the previous year.
In the first half of this year, the Intermarché chain opened three new stores under the Power concept in Poznań, Piekary Śląskie and Milicz.
It has modernised three existing facilities in Śrem, Szczecinek and Oleśnica, to a new concept to offer a wider assortment of items.
The chain has also launched two new petrol stations and two new Intermarché Drive points, which allow customers to order products online and pick them up in a specially designated zone.
Elsewhere, Home and DIY division Bricomarché opened two news stores in the first half and introduced 34 new Bricomats for contactless order collection.
Commenting on Intermarché's performance, Dherment said, "The solid, double-digit growth of the Intermarché network achieved in the last quarter is the result of a gradual return to the market balance in terms of the development of individual segments.
"In addition, the Intermarché network is undoubtedly still reaping tangible benefits from the transformation process started three years ago."
Grupa Muszkieterów expects the second half of the year to be equally intense in terms of the development of e-commerce services, opening new locations within both networks, and implementing its plan to modernise existing facilities.
The company is also optimistic about a further increase in turnover in Intermarché and Bricomarché but said it was "too early to forecast" results for the entire year
"This year will be an opportunity to confirm the Group's leading position as one of the leading retailers in Poland and our strong will to implement further pro-development investments on the market" Dherment said.