The project involves four-laning of the 99.5 km section of the highway.
Blackstone's seven-year-old investment is still deep underwater.
The project has a concession period of 25 years starting October 31, 2005.
Bulk of the IPO proceeds would be utilised to repay debt.
MGAE has now become a wholly owned arm of GMR Hyderabad International.
Initially the deal involves 74 per cent stake buy.
Xander and Norwest had put in Rs 200 crore each in 2010.
Sabre Partners' investment in the infrastructure firm is also underwater.
IRB's order book currently stands at just under $2 billion.
For IDFC Alternatives, this is the third exit since January this year.