Output of core infrastructure industries expanded by 3.9 per cent in July, as compared to 3.2 per cent in the same month last year. According to data released by the government today the six core industries — crude oil, petroleum refinery products, coal, electricity, cement and finished steel registered a 4.5 per cent growth during the first four months of this fiscal as against 4 per cent in April-July, 2009-10. These six segments account for 26.68 per cent of the country's total industrial output.