TVS Motor Company has posted a 50% decline in the Q3 net profit at Rs 5.83 crore for the quarter ended December 31, 2007 as against Rs 11.46 crore reported for the quarter ended December 31, 2006.The decline in profit is mainly attributed to around 45-50% erosion in vehicle sales.In a release to the Bombay Stock Exchange, the company informed that its total income had declined from Rs 952.98 crore for the quarter ended December 31, 2006 to to Rs 896.13 crore for the quarter ended December 31, 2007.