Satyam has entered into a definitive agreement with investors in Nipuna, the BPO subsidiary of the company, for redemption of 50% of the preference shares held by them and the balance 50% to be converted into equity shares."The agreement provides for Satyam to buy out their equity stake for a consideration in the range of $35-45 million by May 2007," Ramalinga Raju, chairman, Satyam, said.