The HSBC manufacturing Purchasing Managers' Index (PMI), which gauges business activity at India's factories but not utilities, fell to 52.9 in July, from 55.0 in June, according to reports.
Reports stated that export orders fell slightly for the first time in nine months.
Manufacturing activity grew at a slower clip in July on the back of power outages, HSBC reportedly said.
There are reports that Manufacturing accounts for around 15% of India's gross domestic product.