The growth rate of eight core industries declined to 2.6% in December 2012, from 4.9% in the same month previous year, due to drop in production of coal, natural gas and fertiliser.

The decline in growth in December 2012 was "on account of negative growth witnessed in the production of coal, natural gas and fertiliser", according to the official data released today.

The cumulative expansion of the eight industries -- crude oil, natural gas, cement, coal, electricity, steel, petroleum refinery products and fertilisers -- was down at 3.3% in April-December 2012 against 4.8% in the same period previous year.

The eight industries have a weightage of 37.9% in the overall Index of Industrial Production (IIP).

Production of natural gas and coal contracted by 14.9% and 0.2%, respectively, in the month under review. Fertiliser output too shrunk by 3.8% against 0.8% growth in December 2011.

Steel and electricity production slowed to 5.2% and 4.4%, respectively, in the reported period against 10.2% and 8.9%, respectively, in the year-ago period.

Cement output slowed to 3.9% from 13.6% in December 2011.

However, Crude oil and petroleum refinery output grew by 1% and 5% against the fall of 5.5% and 0.7%, respectively, in December 2011.

The growth of eight core sector industries had declined to 1.8% in November 2012.