Extract the dates of change of ownership and who the new owner was
The company was founded in 2006. The aim of the company is to develop Synterra's media projects. In September, 2009 Synterra Group of Companies (GC) got operational control of Synterra Media as GC bought 40,01% stocks. GC "Synterra" owns 60% of "Synterra Media". That gives GC the right to make decisions on further development of this project.

In 2010, Megafon under the leadership of Sergey Soldatenkov (Russian: Сергей Владимирович Солдатенков) gained control of Synterra Media with a 60% stake and spun off to Rostelecom several assets including RTKomm.ru, Telecom-Center (renamed Synterra-Media) and Globus-Telecom.

On 22 October 2020, PJSC Rostelecom (Russian: ПАО "Ростелеком") agreed to buy a 100% stake in ZAO Synterra Media (Russian: ЗАО "Синтерра Медиа") from MTT (Russian: АО "Межрегиональный Транзиттелеком" («МТТ»)) for 1.5 billion rubles which allows MTT to focus on the integration of real-time telecom services or Unified Communications and Telecom API. Synterra delivers and distributes media content from the event venues to the television broadcasting companies such as Channel One, VGTRK, NTV, Russia Today, TV Center, Match TV. Both directly and through its subsidiaries, MTT had consolidated its 100% stake in Synterra Media in 2013. As of 2014, MTT, which has 25 million subscribers, competes with Inoventika (Russian: ООО "Иновентика Технолоджес") for cloud computing.
2009 - Synterra Group of Companies
2010 - Megafon
October 22, 2020 - PJSC Rostelecom
Instruction: Extract the dates of change of ownership and who the new owner was
Context: The company was founded in 2006. The aim of the company is to develop Synterra's media projects. In September, 2009 Synterra Group of Companies (GC) got operational control of Synterra Media as GC bought 40,01% stocks. GC "Synterra" owns 60% of "Synterra Media". That gives GC the right to make decisions on further development of this project.

In 2010, Megafon under the leadership of Sergey Soldatenkov (Russian: Сергей Владимирович Солдатенков) gained control of Synterra Media with a 60% stake and spun off to Rostelecom several assets including RTKomm.ru, Telecom-Center (renamed Synterra-Media) and Globus-Telecom.

On 22 October 2020, PJSC Rostelecom (Russian: ПАО "Ростелеком") agreed to buy a 100% stake in ZAO Synterra Media (Russian: ЗАО "Синтерра Медиа") from MTT (Russian: АО "Межрегиональный Транзиттелеком" («МТТ»)) for 1.5 billion rubles which allows MTT to focus on the integration of real-time telecom services or Unified Communications and Telecom API. Synterra delivers and distributes media content from the event venues to the television broadcasting companies such as Channel One, VGTRK, NTV, Russia Today, TV Center, Match TV. Both directly and through its subsidiaries, MTT had consolidated its 100% stake in Synterra Media in 2013. As of 2014, MTT, which has 25 million subscribers, competes with Inoventika (Russian: ООО "Иновентика Технолоджес") for cloud computing.
Response: 2009 - Synterra Group of Companies
2010 - Megafon
October 22, 2020 - PJSC Rostelecom