* Hong Kong market debut likely as soon as later this year -sources. : HONG KONG (Reuters) - China’s largest provider of on-demand online services, Meituan-Dianping, has tapped Bank of America Merrill Lynch (BAML), Goldman Sachs Group Inc (GS.N) and Morgan Stanley (MS.N) to work on a Hong Kong float that could see it list as early as later this year, five people with knowledge of the move said.