Service tax on ocean freight ( with margin )

Dear Frnds...

                            Please give me your opinion as per the facts mentioned below in context with service tax both for the financial year 2010-11 & 2011-12.

A logistic Co. (in Mumbai) (Not a CHA) (Say ABC Co.) provides freight forward services to its client in context of EXPORT goods from India to outside the India by way of SEA.

ABC Co. takes service from shipping co. (Say XYZ Co.) to export goods.

Shipping Co (XYZ Co.) Charges Ocean Freight to logistic Co. (ABC Co.) and not charging Service Tax as it is EXEMPT from Service Tax in case of Ocean Freight.

 Let’s take XYZ Co.

Charges Rs. 100 as Ocean Freight (Without service tax as exempt.)

Handling Charges Rs. 50 on which Service Tax is charged & shown separately in the invoice.

Total Bill amount Rs. 150 to ABC Co. (INVOICE IS IN THE NAME OF ABC Co.)

Now ABC Co. Charges to its client as under

Ocean Freight Rs. 150 (Without service tax on entire amount, even not also on difference amount. i.e. Rs. 50 as not shown separately in the invoice)

Handling Charges Rs. 50 (No service tax was charged on this amount & what we paid as Service tax to XYZ Co. will take credit of that.)

Other Documentation charges Rs 50. (On which service tax is Charged.)

Total Bill amount to the Client Rs. 200

Please Comment weather the treatment of ocean freight is correct?