X5 Retail Group has appointed Lidl executive Frank Michael Mros as director of the company's soft discount stores.

Mros will join the company on 1 June with over 18 years of retail experience in Europe with German discounter Lidl. His career includes a stint as MD of Lidl's German division but he left the role in 2009 after allegations the company was spying on employees. He then took charge of Lidl's UK business for a year.

Of Mros's time in charge of Lidl's domestic division, X5 said: "As MD of Lidl Germany, Mr. Mros was responsible for 3,000 stores, more than 50,000 employees and turnover of approximately EUR15bn."

The retailer also pointed to Mros's role as MD of Lidl in Poland where he led the "successful development of the Polish market".

Andrei Gusev, CEO of X5 Retail Group, added: "Frank's unique experience encompasses the entire retail value chain and will be invaluable to X5.

"His development of the Polish market provides a strong background as he steps in to lead the growth of the soft discounter format, while his track record of optimising operational efficiencies complements our proven Pyaterochka business model."

Last month, the company reported its like-for-like sales were down almost 4% in the first three months of 2012. Like-for-like sales from its soft discount stores fell 2.4%. However, X5 said an increase in promotions and advertising had improved traffic in March.