India's Satyam Computer Services said yesterday it was commencing a competitive bidding process to select an investor to acquire 51 percent stake in the fraud-tainted outsourcer.

Interested bidders will be asked to submit a detailed expression of interest and proof of at least 15 billion rupees ($290 million) by March 20, New York-listed Satyam said in a statement.

Satyam shares jumped as much as 15.3 percent to 48.55 rupees, boosting the company's market value to about $633 million, still just a fraction of the $7 billion it was worth last May.