Interarch Building Products Ltd has reported a 28 per cent increase in net profit to Rs 28.19 crore for the December quarter. Its net profit stood at Rs 21.99 crore in the year-ago period. Total income rose to Rs 369.27 crore in the third quarter of this fiscal year from Rs 321.24 crore in the year-ago period, according to a regulatory filing on Tuesday. It is a turnkey pre-engineered steel construction solution provider.