cenvant in advertising {service tax}

You can take cenvat credit of service tax charged by Advertisement agency. Abatement does not make any difference as we are entitled only for charged amount of service tax.

In the Notification No. 1/2006-Service Tax, shows the abatement rates for few service categories. At the end of the notification, clearly speicfy that

"Provided that this notification shall not apply in cases where, -
(i) the CENVAT credit of duty on inputs or capital goods or the CENVAT credit of
service tax on input services, used for providing such taxable service, has been
taken under the provisions of the CENVAT Credit Rules, 2004; or
(ii) the service provider has availed the benefit under the notification of the
Government of India in the Ministry of Finance (Department of Revenue), No.
12/2003-Service Tax, dated the 20th June, 2003[G.S.R. 503 (E), dated the 20th
June, 2003]."

Also in the above said notification for the service category "Advertizing services" there is not such abatments.
 

I agree with Subbu.