Bankers are encouraging a growing list of international clients to consider tapping the US bond markets in the belief that the current fad for dollar borrowing will become a longer term trend.

Companies based outside the US have raised a record amount in so-called yankee bonds – dollar borrowings marketed to US investors by non-US companies – who have been lured by the extra-cheap financing on offer, even when the proceeds of the deal are swapped back into home currencies.