Wincor Nixdorf, the German manufacturer of automated teller machines (ATM), plans to go public in May. According to the company's chairman Karl-Heinz Stiller, the group is "well prepared" for its listing on the stock exchange. The ATM maker is currently controlled by the US equity firm Kohlberg Kravis Roberts (KKR) and Goldman Sachs Capital Partners. KKR holds the majority stake in Wincor Nixdorf, with Goldman Sachs owning about 30 percent. The remaining 12 percent is held by the German company's own managers. The flotation next month will mark a return to the capital markets for the group which had been listed until the German electronics giant Siemens took control of it in 1990. Since 1999 it has been jointly owned by KKR and Goldmann Sachs.