The Financial Post reports in its Tuesday edition that with most of Canada's biggest banks exposed to the U.S. commercial-property market, the deteriorating quality of some real estate loans could lead to nasty surprises as lenders report fiscal first-quarter results this week. A Bloomberg dispatch to the Post says that commercial-property lending accounts for about 10 per cent of the loan books on average at Canada's five largest banks. With the sector under pressure amid elevated interest rates and plunging valuations, banks have been booking higher provisions for potential credit losses for several quarters. The idiosyncratic nature of which particular loans could go bad makes it hard to predict the scale of coming provisions, said Veritas analyst Nigel D'Souza. While home-price indexes and an array of monthly data provide insight into the health of residential mortgages, there is no equivalent for commercial loans, leaving investors looking at higher-level categories of exposure and making educated predictions. The "U.S. is probably more vulnerable than Canada, office is more vulnerable than other categories, and you are seeing some weakness creep into multifamily residential as well," Mr. D'Souza told the Post.