April 4 (Reuters) - Montreal-based discount store Dollarama forecast annual sales above estimates on Thursday, betting on consistent demand for its discounted groceries and essentials as Canadians weather sticky inflation. The company expects annual comparable store sales growth of 3.5% to 4.5%, largely above analysts' estimates of 3.73%. (Reporting by Annett Mary Manoj in Bengaluru; Editing by Shweta Agarwal)