X5 Retail Group, Russia`s largest food retailer, posted on Thursday a net loss under International Financial Reporting Standards of $82.1 million in January-March against a net profit of $83.3 million a year ago. X5, which operates the Pyaterochka and Perekrestok supermarket and Karusel hypermarket chains across the country, attributed its net loss in the reporting period to the devaluation of the ruble against the U.S. dollar amid the ongoing global economic crisis. Sales declined 8% to $1.87 billion, gross profit slipped 8% to $458.2 million and operating profit fell 5% to $116.9 million, X5 said in a statement. The company`s earnings before interest, taxes, depreciation and amortization (EBITDA) fell 8%, year-on-year, in January-March to $162.7 million, with an EBITDA margin of 8.7%, which was unchanged from the same period of last year. X5 said that the company`s focus on cost controls enabled it to maintain a stable EBITDA margin, an indicator of core profitability, as compared with the same period of last year. "For the rest of the year, we will make every effort to drive efficiency and profitable growth, with a focus on cash generation and deleveraging," X5 said in a statement.