service tax query

amit gupta (DGM accounts and finance)   (24 Points)

26 January 2010  

my company( say named A) is taking back to back construction contract from another company( say named B)which inturn has taken contact from a govt agency (say named G).This govt agency is exempt from service tax as houses to be made are for renting not for sale, so no service tax to be paid by B. please suggest status of A for service tax liability.