Gamma's international presence has broadened following its acquisition of a majority stake in German SIP provider HFO.
The transaction builds on Gamma's European presence in Spain and the Netherlands.
The latest deal sees Gamma take circa 80% of the issued share capital of HFO with an option to acquire the remaining 20% over the next three years.
HFO also sells cloud PBX and mobile services via its network of channel partners in Germany
Gamma had previously identified Germany as a key target market.
It has an overall market of circa 36 million PBX seats (almost twice the UK market size) but a cloud penetration of only 6% (one of the lowest rates in Western Europe).
Gamma CEO Andrew Taylor commented: "The acquisition of HFO provides Gamma with a fantastic opportunity to enter the German market – one of the largest but under-penetrated Cloud PBX markets in Western Europe."
Achim Hager, CEO of HFO, added: "We believe that we can combine our experience of the German market with Gamma’s experience of taking cloud PBX into the channel to develop a leading cloud PBX business in Germany."