DUESSELDORF, Germany - German retailer Metro could restart preparations in September for the stock market listing of a quarter of its Russian cash-and-carry wholesale operation that it postponed due to the Ukraine crisis, sources close to the matter said.

Company and financial sources said relaunching the initial public offering - which had been expected to fetch at least 1 billion euros - would depend on developments in Ukraine and the level of the Russian rouble.

Metro, which wants to use the proceeds to invest in the fast-growing Russian business and other emerging markets and pay down debt, decided in March to delay the stock market listing due to market turmoil over Ukraine.

Metro declined to comment but Chief Executive Olaf Koch has said in the past the planned IPO had been well received by investors and should still proceed if the turmoil on Russian markets abated.

Metro is Russia's fourth-biggest retailer behind X5 , Magnit and French chain Auchan. Its Russian unit made a quarter of Metro's group operating profit in 2013 with sales of about $5 billion, some 9 percent of Metro's total.