The eight core sectors that also include coal, electricity, cement and finished steel, and have a weightage of 37.9 per cent in the Index of Industrial Production (IIP), had grown by 4.2 per cent in April 2011.
The cumulative growth rate of infrastructure industries during 2011-12 also slowed down to 4.4 per cent, from 6.6 per cent in 2010-11, according to the data released by the commerce and industry ministry today.
Natural gas and crude oil production contracted by 11.3 per cent and 1.3 per cent respectively during April.
Petroleum refinery products and fertiliser production shrunk 2.8 per cent and 9.3 per cent respectively during the month.
Coal, Steel and cement output grew by 3.8 per cent, 5.8 per cent and 8.6 per cent in April 2012. In the same month last year, coal output had grown 2.7 per cent, steel - 2.9 per cent and cement - 0.1 per cent.
However, electricity generation slowed down by 4.6 per cent, from 6.4 per cent in April 2011.