* Oil town Calgary biggest contributor to higher prices * Annual price hike 2 pct in decelerating trend OTTAWA, May 9 (Reuters) - New home prices in Canada rose by 0.1 percent in March, as expected, pushed up by the busy real estate market in the western city of Calgary for the second month in a row, according to Statistics Canada data released on Thursday. Prices in Calgary, at the heart of the country's booming oil industry, contributed most to the climb in the new housing price index with a 0.3 percent advance, the agency said. The Toronto-Oshawa region, which has the biggest weighting in the index, saw a 0.1 percent climb following a flat reading in February. Other cities reporting unusually big price hikes for new homes included Regina, Saskatoon and Windsor. Prices fell 0.2 percent in Vancouver. Overall, prices rose in nine cities, stayed unchanged in nine and fell in three. On a year-over-year basis new housing prices in Canada rose by 2 percent in March, the slowest pace since May 2011 and down from 2.1 percent in February. Annual prices have been decelerating since the start of 2013. Canada's government and central bank have long expressed worries about overheating in the housing market, and the associated rise in personal debt levels to record highs. Ottawa has tightened mortgage rules four times. Since the latest intervention in mid-2012, the housing market has shown signs of cooling and the household debt-to-income ratio has stabilized. Statscan's new housing price data exclude condominiums, a particular concern to policymakers.