Once believed to be a dying field, Canadian private radio stations turned a larger than expected profit last year.

Operating revenues totalled $1.6 billion in 2011, up 3.7 per cent from 2010, according to a Statistics Canada report released Tuesday.

The gains were a departure from the industry's recent history, after revenues decreased by 5 per cent in 2009 during the economic downturn.

97 per cent of the private radio stations' revenue came from advertising, contributing to the $313 million in profits last year. While both AM and FM stations showed strong profitability, the number of AM stations continued to decline with 16 going off air since 2009.

Out of all of the provinces, Ontario private radio broadcasters were the most profitable, while Quebec and Atlantic Canada saw profits decrease.