Mumbai-based JBF Industries, a polyster chips manufacturing major, hasposted an increase of 29.78% in its net profit at Rs 30.33 crore for the quarter ended December, 2007 compared with Rs 23.37 crore in the corresponding quarter in the previous year. The company's net sales during the period rose to Rs 496.28 crore from Rs 414.67 crore, up 19.68%.The operating profit grew to Rs 69.73 crore, up 36% from Rs 51.25crore. The company's shares closed at Rs 189.70, up 1.99% in theweak Mumbai market on Thursday.