LONDON (Dow Jones)--WPP PLC (WPP.LN), a communications and marketing services group, said Monday that WPP Digital, its digital investment arm, has acquired a minority stake in Leading Smart Holdings Ltd., a BVI company, which has a controlling interest in the parent company of Moment Systems, the leading digital advertising measurement company in China. MAIN FACTS: -Moment Systems was founded in 2006 in Beijing and currently employs 90 people. -Shares closed Friday at 642.5 pence. -By Tommy Stubbington, Dow Jones Newswires; 44-20-7842-9268; tommy.stubbington@dowjones.com (END) Dow Jones Newswires July 19, 2010 02:18 ET (06:18 GMT)