Balkan telecoms and media company United Group, owned by private equity firm BC Partners, announced on Thursday it had agreed to acquire Bulgaria’s leading telecoms operator Vivacom.

United Group has sealed a 1.2 billion euros deal ($1.3 billion) to acquire Vivacom, which was put up for sale this year, two sources familiar with the transaction said. The deal was also officially confirmed in a press release later in the day.

The deal comes after United Group acquired Croatian telecoms operator Tele2 Croatia for 220 million euros ($243 million) in May as part of its plans to expand in south-eastern Europe, Reuters reports.

United Group, Vivacom and BC Partners said in a joint statement that the deal was expected to close in the second quarter of next year, “subject to conditions, including receipt of applicable anti-trust approvals”.

A consortium led by Bulgarian businessman Spas Roussev took control of Vivacom from Russia’s VTB Bank (VTBR.MM) in 2016 after bidding 330 million euros in an auction the previous year. It also took on about 450 million euros of Vivacom debt. Russian businessman Dmitri Kosarev, who had a stake in a holding company that owned Vivacom, has disputed this sale, which he says wiped out his investment, in various courts. Kosarev’s company, Empreno Ventures, said in a statement on Thursday it has also issued legal proceedings in Luxembourg against BC Partners and United Group over the Vivacom purchase.

United Group, which is owned by London-based private equity firm BC Partners, currently offers pay TV, internet and telecommunications services in the six former Yugoslav republics. Vivacom, formerly the state-owned fixed-line monopoly Bulgarian Telecommunications Company prior to its privatization in 2004, offers broadly the same spectrum of services.

“Vivacom is a well-run company with strong management and I am excited at the opportunities we have to build an even stronger business. Bulgaria is an attractive market and this acquisition will enable us to diversify the Group further,” United Group CEO Victoriya Boklag said in a statement.

Nikos Stathopoulos, Partner at BC Partners commented, “When we invested in United Group, we identified its business model, technology and regional leadership as key drivers for organic growth, accelerated by acquiring and integrating local companies. With Vivacom, we are pleased to acquire a dynamic telecom operator in a vibrant economy and a growing market that enables us to expand our geographic reach across Europe.”

Vivacom chairperson of the board and majority shareholder Spas Roussev described the transaction as “a great success and a great opportunity for Vivacom, its clients, and more generally for Bulgaria,” adding that “Vivacom will play a big role in the future development of United Group, their leading regional telecom and media platform.”

The transaction is expected to close in the second quarter of 2020, subject to regulatory approvals.

This is the second major transaction involving one of Bulgaria’s mobile carriers in the past 18 months, after Norway’s Telenor sold its Central and Eastern European telecommunications business, which included Telenor Bulgaria, to Czech investment conglomerate PPF Group for 2.8 billion euro in March 2018.