Service tax input credit

Hi,

As per Rule 4 of CCR, 2004, A service provider can avail CENVAT credit on inputs upon receipt of inputs in the premises of the provider of output service.

If output services are provided to a unit in SEZ or Developer of SEZ, where service tax is exempted. Are we eligible to claim cenvat credit on inputs fully or pro rata to the extent of taxable services provided to Non-Sez unit. Pl clarify.