Cyril Amarchand Mangaldas and Simpson Thacher & Bartlett have advised U.S. investment fund Blackstone on its $359 million purchase of a majority stake in India's R Systems International from the IT services company's promoters, who were counseled by AZB & Partners.

Reuters reported that Blackstone would be launching a conditional de-listing offer at 246 rupees per share, with the fund seeking regulatory approval from the Indian market regulator. It added that Satinder Singh Rekhi, one of R Systems' promoters selling their stake, would be a non-executive advisor to Blackstone.

The CAM team was led by partners Shishir Vayttaden and Gautam Gandotra, with support from partners Abhishek Sharma, Abhilash Pillai, Partner, Ashish Jain, Arun Prabhu, Anirban Mohapatra, Richa Mohanty Rao, Avaantika Kakkar, Kaustav Kundu, and Bharat Vasani.