The firm paid 8.30 rupees per share.
Estate Management Services Limited, a unit of Sunshine Holdings Plc which has 75.6 percent stake in Hatton has an option to sell the remaining stake within three months also for 8.30 rupees.
NDB Investment Bank was advisor to the deal.
Lotus Renewables, is part of a Singapore-based energy group, which already has hydro power investments in Sri Lanka.