The news triggered the company's share price to rise 6.76 per cent on the Bombay Stock Exchange (BSE) to close at Rs 43.45 on Tuesday. Warburg Pincus has a stake in WNS, a BPO company, while Blackstone has a majority stake in Intelenet.

An official spokesperson for Firstsource declined to comment on the issue.

However, sources close to the development said that Temasek has not informed the company of any intention to sell its holdings. They added that Temasek had been approached by quite a few private equity funds evincing their interest in the BPO, but "it was not actively looking at selling its stake in the BPO currently."

"By the end of the day, they are private equity funds and they will look at monetising their holdings in portfolio companies," said a source.

A senior executive of a private equity fund said they have been approached with the proposal from the Singapore-based private equity fund. "It's very early to talk about the transaction as it is in the preliminary stage," he added.

Meanwhile, fund officials at Sequoia said they were neither looking to sell their stake nor increase their holding.

Seacrest, the other investor, recently bought a stake in the company by acquiring shares of Deutsche Securities and Shriane.  ICICI Bank [Get Quote] cannot sell its shares as its 19.48 per cent stake is locked-in for three years till 2010.

"The current valuation of Firstsource is 32 times its P/E ratio trailing 12 months. However, the seller would like to sell its stake at the listing price of the company's IPO and not the current trading price," said a senior executive with a leading domestic investment bank.

Apart from ICICI Bank (which holds 26.80 per cent), the other shareholders are Temasek Holdings (21.51 per cent ), Metavante Investments(20.07 per cent), Westbridge Ventures (now Sequoia holds 4.56 per cent) and Seacrest Investment (4.43 per cent).