The Globe and Mail reports in its Monday edition that the banks are seeing fewer borrowers adding unpaid interest to their mortgage balances, but lenders still have $110-billion of outstanding loans that are ballooning because the monthly payments do not cover the interest costs. The Globe's Rachelle Younglai writes that when a mortgage increases in size that way it is known as negative amortization. Three of Canada's major banks offer mortgages that permit negative amortization -- a product the federal bank regulator is now calling "dangerous." BMO, TD and CIBC had $110-billion in loans in negative amortization in their fourth quarter ended Oct. 31, according to their recent financial results. That was down from $130-billion in the third quarter, suggesting their borrowers were making higher monthly payments to cover interest costs or had sold their properties and discharged their mortgages. The negative amortization trend began last year as interest rates soared, leaving some borrowers with variable-rate mortgages facing the possibility of far higher payments. Some banks allowed their customers to keep their payments stable by reducing the amount going toward the loan principal and even not paying the interest.