Tata Motors stock witnessed brisk activity in early trades today on the BSE. 10 lakh shares changed hands at a price of Rs 660 in a block deal at the counter. The stock, which, opened at Rs 664, touched a high of Rs 668 and was trading at Rs 662, up nearly 2% early noon trades. Market is abuzz with talks that high volume at the coutner could be a result of Tata group's stratgy to increase the promotor's holding in the group companies.