The IT sector accounts for 60 per cent of the operational Special Economic Zones, but make up for only 18 per cent of the total exports from these enclaves.
Exports from 114 operational SEZs in the last fiscal were valued at Rs 2.20 lakh crore.
While Reliance Petroleum's SEZ refinery contributed Rs 70,000 crore, total exports from all the 69 IT SEZs were about Rs 40,000 crore.
"Though their number is large, most of the IT-specific SEZs are small given the fact that the minimum land requirement for them is 10 hectares each," a Commerce Ministry official said.
The land area requirement for SEZs in sectors other than IT, bio-technology and gems and jewellery is 100 hectares. For the multi-product SEZ, a minimum of 1,000 hectares is needed.
The SEZs, which are allowed income tax exemption have received total investment of Rs 1.66 lakh crore, most of which came after notification of the SEZ Act in 2006.
Exports from the IT related zones are allowed full deduction from profits and gains from export for the first five years.
For the subsequent five years, 50 per cent income tax is levied on the export income. However, the Direct Tax Code pending before Parliament seeks to do away with the concessions from 2012.
Most of the SEZs, which have received approvals or are notified, belong to the specific sectors with IT and ITeS claiming the lion's share.