Tokyo stocks lost momentum as the afternoon session opened on Thursday, with the Nikkei Stock Average moving around 10,086. The benchmark briefly fell below Wednesday's close, Japan's online edition Nikkei reported. HSBC Corp. said during the lunch break that China's preliminary purchasing managers' index for March reached 48.1, down 1.5 points from the final reading for February. This raised concerns that the Chinese economy is slowing down, prompting investors to sell some China-dependent stocks, including Fanuc Corp. (6954). The broader Topix index also trimmed its gains.