Similarly, the operating profit of subsidiaries increased by 52% to Rs 27,701 crore during the quarter ended December last year. The operating profit margin of subsidiary companies increased by 369 basis points to 19.81% from 16.12% during the quarter ended December in 2009 despite the fact that the interest cost of the group increased by 64% to Rs 4,752 crore in the quarter ended December 2010 from Rs 2,896 crore during the same quarter in 2009. The top five companies according to subsidiaries sales in the quarter ended December were Tata Steel, Tata Motors, Bharti Airtel, Adani Enterprise and Grasim Industries. The highest growth in sales was registered in the case of Bharti Airtels 17 subsidiaries. The sales of the 17 subsidiaries of Bharti Airtel increased by 300% to Rs 4,976 crore during the quarter ended December last year from the level of 1,550 crore during the same quarter in 2009. The operating profit margin of the 17 subsidiaries of Bharti Airtel decreased by 21.12 percentage points to 28.81% during the quarter ended December 2010 as compared with 49.93% in the quarter ended December 2009.
On the other hand the top five companies in terms of subsidiaries operating profit were Tata Motors, Cairn India, Sterlite Industries, Bharti Airtel and Reliance Communications. Here the highest growth in subsidiaries operating profit was seen in the case of Cairn India.