The Bank of Nova Scotia, Canada’s third largest bank, has applied to open a Miami office. It filed state and federal applications to do transactions for its Canadian customers in the region. Having a Miami office would also allow the bank to use Florida properties as collateral for loans. The bank also has an international agency office in Houston and a branch in Puerto Rico. Ryan Stokes, who reviews international bank applications for the Florida Office of Financial Regulation, said the Bank of Nova Scotia had an office in Miami from 1978 to 1988 and from 1990 to 1993.