** Shares of Canada-based online retailing services provider down 7.5 pct at C$159.23 after co reports slower Q1 growth rate
** U.S.-listed shares down 8.1 pct; both shares set for biggest pct loss in more than 6 months at current levels
** Gross merchandise volume (GMV), a growth indicator in the e-commerce industry, grows 64 pct in Q1 vs 81 pct year-ago
** Merchant solution revenue, largely obtained from fees charged to merchants on orders, grows 75 pct vs 92 pct last year
** SHOP’s Q1 net loss widens
** So far this year, company’s Toronto shares had risen 24.7 pct (Reporting by Anirban Paul)