HONG KONG, April 19 (Reuters) - Private equity firm Blackstone Inc is nearing a deal to sell its controlling stake in South Korean wholesale drug distributor Geo-Young to North Asian buyout fund MBK Partners for over $1 billion, three sources said.

Representatives from Blackstone, MBK and Geo-Young declined to comment. (Reporting by Kane Wu in Hong Kong; additional reporting by Hyunsu Yim in Seoul; Editing by Muralikumar Anantharaman)