VANCOUVER, British Columbia (Reuters) - There was a time when people said Canada's "Big Six" banks were all the same. That has never been less so than now, analysts say.

If you had chosen to put money into Toronto-Dominion Bank at the start of this year, your investment now would be up four percent. If you had gone for Canadian Imperial Bank of Commerce, it would be down a whopping 25 percent.

The differences between the banks are only expected to become more stark next year if the global credit crunch continues to underline which of them embraced riskier business practices, and as lenders' traditionally solid Canadian retail operations face tougher conditions.

"Years ago people used to think of the Canadian banks as monolithic. Whatever one did, so did the other. That is just not the case anymore with strategies and managements really having diverged in recent years," said James Cole, senior vice president and portfolio manager at fund manager AIC.

He points to TD, Canada's second-largest bank, which had a tumultuous 2002, when its results were buffeted by big loans to the troubled telecom sector, but which subsequently pulled in its horns and made a pledge to stick to lower risk areas of banking.

As a result TD is the only one of Canada's big banks, and one of the few in the world, not to have any writedowns in 2007 for investments in some way linked to the default-hit US subprime housing market.

By comparison, CIBC, Canada's number five bank, revealed it had C$11 billion ($10.8 billion) exposed to the subprime market, and analysts say it might have to write off C$2 billion of that in the first half of next year.

"We were sorely disappointed in CIBC and the extent of its exposure to subprime," BMO Capital Markets analyst Ian de Verteuil said in a report this week. "We had hoped that the relatively young management team was well along the path toward changing the bank's culture."