LightSpeed, a Canadian retail software startup, plans to introduce a payments system and boost its international presence with $35 million in funding from INovia Capital and Accel Partners Ltd. The investment brings Montreal-based LightSpeed’s total to $65 million. Accel led a $30 million round in 2012. LightSpeed builds software that retailers can use to combine in-store and online sales systems, track inventory and collect data on shoppers. Lightspeed’s customers, which include Fender Musical Instruments Corp. and Leica Camera AG, process an average of $500,000 each year in 20,000 stores, Chief Executive Officer Dax Dasilva said in an interview.