Rules stipulating that foreign supermarkets will have to source 30 percent of produce from smaller industries cannot be restricted to the Indian market, as this would violate World Trade Organisation guidelines, a senior official said.

"It would violate WTO guidelines," Industry Secretary P.K. Chaudhary told Reuters on Friday.

The policy came with a condition to source from smaller industries as a way of spreading the benefits of the policy change to Indian firms, but New Delhi cannot by law mandate that the sourcing comes from Indian companies, he said.

The government on Thursday approved 51 percent foreign direct investment in the supermarket sector, paving the entry of firms such as Wal-Mart, Tesco and Carrefour into one of the world's largest untapped markets.

"We cannot put in a local sourcing clause in the guidelines, which will come out next week but we're hoping economics will dictate that a chunk of the sourcing will be local," said another official from the industry ministry, who did not want to be quoted.

Source: Reuters