The output of India's eight major industries during last month grew by 3.6 per cent from a rise of 2.8 per cent reported in April 2017, official data showed on Friday.

The Eight Core Industries (ECI) data which represents the output of major industrial sectors like coal, steel, cement and electricity had grown by 5.2 per cent in the corresponding month of 2016.

"The combined Index of ECI stands at 126.4 in May 2017, which was 3.6 per cent higher compared with the index of May 2016. Its cumulative growth during April to May, 2017-18, was 3.2 per cent," the Commerce and Industry Ministry, which releases the figures, said.

The ECI index comprises 40.27 per cent weightage of the Index of Industrial Production (IIP). Recently, the base year of ECI index was revised from 2004-05 to 2011-12. 

On a sector-specific basis, petroleum refinery production, which has the highest weightage of 28.03 per cent, edged up by 5.4 per cent in May 2017 as compared with the corresponding month of last year.

Electricity generation, which has the second highest weightage of 19.85 per, rose by 6.4 per cent last month.

Steel production, the third most important component with weightage of 17.92 per cent, increased by 3.7 per cent during the month under review. Conversely, coal mining, with a 10.33 per cent weightage, decreased by 3.3 per cent in May 2017.

Extraction of crude oil, which has a 8.98 per cent weightage, was inched up by 0.7 per cent during the month under consideration.

On the other hand, the sub-index for natural gas output, with a weightage of 6.88 per cent stood higher by 4.5 per cent.

Besides, cement production, which has the weightage of 5.37 per cent, rose by 1.8 per cent in May 2017.

In contrast, fertiliser manufacturing, which has the least weightage of only 2.63 per cent, decreased by 6.5 per cent.