Fraud-hit Satyam Computer Services Ltd's annual revenues appear to be about $1.5 billion to $1.7 billion, three sources who have analysed data provided by the outsourcing firm to bidders said on Thursday.

The number is sharply lower than the $2.14 billion the Indian company had reported for the fiscal year to March 2008, before the revelation of India's biggest corporate fraud.

We have analysed the data and feel that this is the revenue level for the firm, said one source who declined to be named as he was not authorised to speak to the media.

Satyam was plunged into crisis on January 7 when its founder quit as chairman, saying profits had been falsified for years, revenues overstated and more than $1 billion in cash and equivalents did not exist.

A government-appointed board tasked with rescuing the firm decided to sell a controlling stake in the firm, once ranked as India's fourth-largest outsourcer, and appointed Goldman Sachs and Indian investment bank Avendus to advise it.

The sources said they were still assessing the profitability of Satyam ahead of finalising bids for a 51 percent stake.

Bids will be submitted and opened on April 13, and Satyam has said a winner can be announced the same day.

As well profit and revenue, bidders need to make an assessment of several uncertainties, including potential legal liabilities arising from lawsuits filed in the United States by shareholders.

Satyam has not reported earnings since reporting July-September numbers in October as its accounts are in the process of being restated.

Indian media have reported more than 40 clients of Satyam have left the firm since the revelation of the fraud, but Satyam has declined comment.

Indian engineering and construction firm Larsen & Toubro, which has built up a 12 percent stake in Satyam, mid-sized outsourcer Tech Mahindra and private equity firm W.L. Ross & Co are among the suitors.

Indian media have reported IT services provider Cognizant Technology Solutions has also joined the race.