[1] Mercator Partners, a special purpose acquisition company bought Global Internetworking Inc. in April 2005 and European Telecommunications & Technology in 2006.

[4] It then acquired PacketExchange, a privately held UK company and operator of a global IP backbone, in June 2011 for $20 million in cash.

[10] In October 2014, GTT announced it had closed the acquisition of UNSi, a communications company providing data services to large enterprise and carrier clients.

[12] On October 22, 2015, GTT acquired One Source Networks (OSN), a provider of data, Internet, Session Initiation Protocol (SIP) trunking and managed services.

[18] On June 19, GTT announced it was acquiring Perseus Telecom, a provider of low latency services for the financial market industry, for $37.5 million.

[24] On March 12, GTT expanded its Canadian footprint by acquiring Toronto-based telecommunications company Accelerated Connections.

[25] On October 1, GTT acquired Cary, NC-based Access Point, a provider of communications services in the US market.

The division consists of a pan-European, North American, and subsea fiber network and data center assets and associated infrastructure services provided to customers which were acquired by GTT through the Hibernia, Interoute and KPN International acquisitions.

[28] On August 2, 2021, The New York Stock Exchange delisted GTT Communications' shares after it failed to file its quarterly and annual results.

In November 2024 the company announced the virtualization of its Managed Dedicated Internet Access service, enabled through the GTT Envision platform.