Bharti Airtel Ltd wholly-owned subsidiary Bharti International (Singapore) Pte. Ltd has bought an additional 6.3% stake in Bangladesh’s second-largest telecom operator Robi Axiata Ltd for an undisclosed amount from Japanese telecom major NTT Docomo Inc.

Bharti Airtel’s stake in Robi Axiata now stands at 31.3%. Malaysia-based Axiata Group Berhad owns the remaining 68.7% stake in the company.

The deal precedes the Bangladesh-based telecom operator’s initial public offering (IPO) on the Dhaka and Chittagong stock exchanges, the prospectus for which was filed in March. The stake sale also marked an exit for NTT Docomo. Robi Axiata’s larger rival Grameen phone Ltd is the only mobile operator listed on the country’s stock exchanges.

Axiata Group had in February said the subsidiary will go public with an IPO worth 5.24 billion Bangladeshi taka, or ₹465 crore, for a 10% stake.

Bharti Airtel had merged its Bangladesh-based unit with Robi Axiata in November 2016 to strengthen its position in the country’s mobile industry.