A severe shortage of dong, Vietnam’s currency, has been causing headaches for foreign businesses in the country as the government tries to control inflation by reining in the supply of notes.

In one sign of the currency crunch, last week Hanoi was forced to give special permission to Morgan Stanley to pay $217m in dollars for a 10 per cent stake in PetroVietnam Finance Corp, instead of making the payment in dong, as is normally required by law.