Hi Pradeep
I feel the problem is with the lookup of currency data into the DSO maintained in transformations.
This is due to the fact that for each record the system has to go back and make a lookup on the DSO to find the corresponding entry.
Can you please mention what is the data volume of DSO into which the currency type is looked upon.
Also please check the job details using Trnx: ST13 and background overview analysis function to check where exactly the job is spending time.
Ashish