That is a huge 1872 per cent return on investment in a period of less than 18 months. If the issue gets priced at Rs 510, Citicorp's return will jump to 2266 per cent.

Of course, Citicorp will not realise this return entirely, since it is selling only a small portion of its investment in the company through the IPO.

Suzlon's initial public issue of 29.34 million shares includes an offer for sale of 2.58 million shares by Citicorp. That will still leave Citicorp with 20.6 million shares.

In fact, Citicorp is not the only player that has benefited in a big way. ChrysCapital, another private equity investor, bought shares in August last year at an effective price of Rs 27.1 per share.

Unlike Citicorp, which is offloading shares through the IPO, ChrysCapital has already sold about 60 per cent of what it held in Suzlon to other foreign investors at an average price of Rs 385.6 per share.

ChrysCapital continues to hold 7.5 million shares in the company, which makes its total return on Suzlon investment from 1380 to 1509 per cent, based on the price band of Rs 425-510.

Both Citicorp and ChrysCapital have invested Rs 50 crore (Rs 500 million) in Suzlon for a 9.6 and 7.1 per cent stake, respectively. This puts Suzlon's valuation at Rs 522 crore (Rs 5.22 billion) and Rs 707 crore (Rs 7.07 billion), respectively.

Based on the IPO price band, Suzlon's equity is valued between Rs 12,220 crore (Rs 122.20 billion) and Rs 14,664 crore (Rs 146.64 billion), an increase of between 2200 and 2700 per cent, respectively.