Report says that the deal may be valued at close to $1.45 billion inclusive of debt.
The negotiations are in the final stages and a definitive sharesale agreement is expected in the next two-three weeks, says report.
The other contender in the race was Greenko Group Plc, a Hyderabad-based renewable energy company controlled by Singapore's sovereign wealth fund GIC.
Welspun Renewables Energy Pvt Ltd (WREPL) is currently operating 685 mw of wind and solar energy projects across eight states, according to the daily.
Another 200 mw is expected to get commissioned by this June-end while a further 257 mw is due by October-November.
Tata Power Company Ltd is currently trading at Rs. 70.7, up by Rs. 0.15 or 0.21% from its previous closing of Rs. 70.55 on the BSE.
The scrip opened at Rs. 70.6 and has touched a high and low of Rs. 71 and Rs. 69.4 respectively. So far 953013(NSE+BSE) shares were traded on the counter. The current market cap of the company is Rs. 19081.16 crore.
The BSE group 'A' stock of face value Rs. 1 has touched a 52 week high of Rs. 79.8 on 20-May-2015 and a 52 week low of Rs. 55 on 12-Feb-2016. Last one week high and low of the scrip stood at Rs. 72.45 and Rs. 68.45 respectively.
The promoters holding in the company stood at 33.02 % while Institutions and Non-Institutions held 50.7 % and 16.27 % respectively.
The stock is currently trading above its 200 DMA.