Kismet, which financed the deal with its own funds and a loan from Russian top lender Sberbank, said Russian Towers would now become part of New Towers, which already holds assets from tower company Vertical and Megafon's First Tower Company.

Following the incorporation of Russian Towers, Kismet Capital Group will hold a 65% shareholding in New Towers, with Megafon taking a 25% stake and Vertical the remainder, Kismet said.

Faced with straitened revenue growth and stubbornly high debt built up during the last network upgrade, telecoms companies across Europe are looking to raise cash by selling their tower portfolios, or creating future income streams through spinning off those assets.

Russia's biggest mobile operator MTS in November said it may sell its tower assets and Rostelecom has plans to do the same.

Telecoms firm Veon, whose primary market is Russia, last month finalised a $970 million deal to sell its portfolio.

Russian Towers' portfolio comprises around 7,200 antenna-mast structures across Russia, Kismet said. The merger of the three tower assets takes New Towers' structures to more than 30,000.

Kismet founder Ivan Tavrin, a former Megafon CEO, said the acquisition was part of a long-term strategy to develop its tower business.

"We plan to make the combined company public and will be open to entering new geographies," he said in a statement.

As part of the deal to merge the companies, Megafon's First Tower Company was valued at 94.2 billion roubles ($1.26 billion), the parties said in October.

($1 = 75.0160 roubles)

(Reporting by Gleb Stolyarov; writing by Alexander Marrow; editing by Jason Neely)