Canadian Western Bank (CWB.TO) reported a 9.7 per cent fall in its fourth-quarter earnings as low commodity prices weighed on its oil and gas loan portfolio.

The company, which mainly lends to clients in the western provinces of Canada, including oil-rich Alberta, said its total allowance for credit losses increased almost 10 per cent to $103.8 million in the quarter ended Oct. 31.

The bank's net income attributable to shareholders fell to $47.8 million, or 54 Canadian cents per share, from $53 million, or 66 Canadian cents per share, a year earlier.

A nearly 55 per cent drop in oil prices since mid-2014 has forced banks to cut credit lines for oil and gas companies.