Blackstone Group LP (NYSE: BX) is buying the majority of the private-sector business-process outsourcing operation from Serco Group plc (LON: SRP) for £250m ($387 Million) in cash, marking it the PE firm’s largest deal in India.

The target provides back-office services, including transaction processing, for the financial services, retail and healthcare sectors.  The business is expected to generate about $364 million in revenue for 2015.

Serco, a Hampshire, England-based outsourcing firm originally acquired the business from Blackstone in 2011 for $634 million when it was known as Intelenet. Blackstone is planning on renaming the target Intelenet Global Services.

Serco is planning on divesting its remaining private sector BPO business so it can focus on the company’s public sector work.