CHENNAI: The net profit of Tube Investments of India shot up to Rs. 42.07 crore during the quarter ended September 30, 2008, from Rs. 15.72 crore. Sales were higher at Rs. 635.76 crore against Rs. 424.64 crore. The improved profitability of all businesses during the period under review has been due to focus on cost reduction, product mix and substantially improving customer satisfaction, says the company in a release.