Canadian Imperial Bank of Commerce could have up to C$10 billion ($10 billion) in hedged exposure to the U.S. subprime mortgage sector, a newspaper said on Friday.

Citing people who have studied the dealings of Canada's fourth-biggest bank, The Globe and Mail reported that only a fraction of that amount is believed at risk of a writedown because the hedges have been spread among many different parties.

It said that if some of those hedging partners were to collapse, and the bank had to take a charge, the risk would be limited to between C$1 billion and C$3 billion.

Earlier in the month, CIBC said it would take a fourth-quarter writedown of C$463 million before tax on various securities tied to the troubled U.S. mortgage market. The bank reports results next week.

The Globe said CIBC officials declined to comment on the matter.

($1=$1 Canadian) (Reporting by Jonathan Spicer; Editing by Scott Anderson)