Hindalco Industries' consolidated net profit for FY11 dipped 37.4% to Rs 2,456 crore primarily on increased expenses on raw material and higher interest outgo.
The Aditya Birla Group flagship firm had reported Rs 3,925 crore net profit in 2009-10, it said in a statement.
Raw material consumption of Hindalco, which produces aluminium and copper, rose to Rs 47,416 crore in FY11 from Rs 38,100 crore in FY10.
"Interest expenses increased from Rs 1,104 crore to Rs 1,839 crore mainly due to one-time debt issuance cost related to the refinancing of $4.8 billion at Novelis in December 2010 and consequent higher interest in Q4," it said.
Net sales of the company, however, rose by 19% to Rs 72,078 crore, its highest-ever, over Rs 60,708 crore clocked in the previous fiscal on increased volume, improved price and higher commodity prices.
Recording an increase of 17%, company's aluminium business contributed Rs 56,084 crore to the net sales. Copper business contributed Rs 15,887 crore, up by 26% over the previous fiscal.