The Royal Bank of Canada moved Wednesday to unload hundreds of millions of dollars worth of commercial real-estate debt seized from clients in recent days, trying to protect itself from pain spreading through the mortgage market.

RBC, Canada’s largest bank by assets, was seeking bids Wednesday for more than $600m of debt tied to commercial mortgages, according to people familiar with the matter. In a sign of how quickly the market is deteriorating and the pressure institutions feel to quickly deal with the situation, the bank is expected to choose a buyer by the end of the day.