Two big Canadian insurance companies reported losses Thursday.

Toronto-based Manulife Financial Corp. reported a loss of $172 million, or 12 cents a share, down from a profit of $510 million or 33 cents a share in the same period last year.

At the same time, Sun Life Financial Inc. reported a net loss of $140 million or 25 cents per share for the July-September period.

That was better than the net loss of $396 million or 71 cents per share in the third quarter of 2008.

The Toronto-based company more than tripled revenue to $8.8 billion from $2.6 billion, after increasing its operations in Canada and the United States.

Both companies say adding to their losses was the need to set aside money to cover what the industry calls "changing actuarial assumptions." That's a complicated area, but two examples include assuming increasing demand for products that provide guaranteed income and clients keeping up insurance policies as they live longer.

The need to invest more now to cover those future increases in payouts cost Manulife $783 million and Sun Life $513 million. Shares in Manulife were down 90 cents, or more than four per cent, to $19.69 on the Toronto Stock Exchange. Sun Life lost $1.91, or more than six per cent, to trade at $28.20.