This was agreed at the Monetary Policy Committee meeting on 2 October and is in addition to an $18 billion package already approved for the same purpose.
The committee said the foreign currency auction that was introduced on 23 June had brought about economic stability which it expected to continue during the last quarter of the year.
So far US$320.3 million has been allotted mainly for raw materials, machinery and equipment.
The committee also agreed to maintain the $5 000 a day mobile money transaction limit with a weekly limit of $35 000.
It, however, said the limits will be reviewed continuously in line with requirements and convenience of the transacting public.
The committee said all financial transactions will be closely monitored.
Full MPC Statement: