Anil Agarwal, billionaire founder of the Vedanta Group, has pledged his stake in a cash-rich Indian unit to help sweeten terms for a takeover attempt that's key to his debt-repayment plans. The London-based Vedanta Resources will now seek to buy 17.51 per cent of Mumbai-listed Vedanta at Rs.235 ($3.24) a share, it said in an exchange filing Tuesday. That's up from the previous 10 per cent at Rs.160 a piece.