The criminal investigation into the financial scandal at Indian outsourcer Satyam Computer Services advanced on Tuesday with the country's Central Bureau of Investigation (CBI) filing charges against nine people, including six former employees of the company.

The charges were filed in a court in Hyderabad where Satyam has its headquarters.

Among those charged are the company's former chairman, B. Ramalinga Raju, his brother and former managing director, B. Rama Raju, and Vadlamani Srinivas, former chief financial officer.

Satyam went into a crisis in January after Ramalinga Raju said that the company's profits had been over-stated for several years.

The accused have been charged for a number of offences including criminal conspiracy, cheating, forgery, falsification of accounts and causing disappearance of evidence, the CBI said in a statement on Tuesday.

Satyam's government-appointed board is planning to announce the winning bidder for a majority stake in the company on Monday, according to informed sources. The new board was appointed after the government superseded Satyam's board following the revelation of a scandal in the company.

Satyam's customers would prefer that the new investor is a large IT services company with a proven track record of managing a multibillion dollar business, analysts said.

Some bidders opted out from the auction of the majority stake in Satyam, citing lack of sufficient information on the company's finances.

Satyam's accounts are being re-instated, and there isn't an indication as to when this process will be complete. The company is also facing class-action suits from US investors.