Service tax on sub contract(in mfg industries)

Pls find the below mentioned eg and opiened on it at service tax point of view?

X & CO (a processor- who converted the raw material of Y Ltd (a manufacture) into sami finished (WIP) stage ) charges Rs. 10 lakhs to Y LTD for fabrication work. Y ltd further process the material and bring it into finished stage. it is a tailor made product hence after completion Y Ltd need to install it at site of the customer. while work of Erection & Commissiong (Installation) Y Ltd charge service tax on installation charges. while sale of the product Y Ltd charge Excise duty on sale of material.

Please check whether X & Co is liable to charge service tax in above case as it is a sub contractor who process the materail recd from main contractor (Y LTD).

Thanks in Advance

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