Tata Chemicals today reported a marginal (1.3%) increase in net profit at Rs 97.81 crore for the third quarter ended December 31, 2005 when compared with Rs 96.59 crore for the quarter ended December 31, 2004.According to a release issued by the company to the BSE, total income rose 18.7% to Rs 1,268.63 crore in Q3FY06 from Rs 1,068.60 crore in Q3FY05.