WM Tech's planned US$1 billion (HK$7.8 billion) initial public offering in Hong Kong is facing delays as the city's bourse questions the supermarket owner on its business operations. The Beijing-based company behind the Wumart chain and Metro AG's outlets in China is addressing queries Hong Kong Exchanges and Clearing (0388) raised during the IPO vetting process, the people said. Separately, the planned US IPO of Beijing DMall has also come to a standstill, according to people familiar with the matter. The online retail service provider is controlled by Zhang Wenzhong, the chairman and founder of WM Tech. Dmall provides retail…