The growth rate of India's core infrastructure industries, which includes power, coal, steel, fertilizer, natural gas and cement, slipped to 2.3 per cent in May this year, newly announced official figures revealed.

In May 2012, the country's eight core industries had registered a growth rate of 7.2 per cent.

The industry ministry blamed negative growth rates in sectors like coal and fertilizer for the overall sluggish growth.

The ministry said in a statement, "The decline in the growth rate in May 2013 was mainly on account of negative growth witnessed in the production of coal, crude oil, natural gas and fertilizer."

Production of coal slipped 3.3 per cent in May 2013 as against a rise of 9.6 per cent in the corresponding month of 2012.

During April-May this year, coal production slipped to -0.1 per cent, while production of crude oil, natural gas and fertilizer fell to -1.8 per cent, -18.1 per cent and -2.2 per cent, respectively.

The eight core industries have a combined weight of 37.90 per cent in the Index of Industrial Production (IIP).