Billionaire investor Wilbur Ross is one of four bidders expected to participate in an auction on Monday for Satyam Computer Services, the scandal-tainted Indian outsourcing group.

The news came as India's federal police yesterday formally charged B. Ramalinga Raju, Satyam's former chairman, along with two of his brothers, two Price Waterhouse auditors and four others with criminal conspiracy, in a widening of the probe into the scandal.