GTT Atlantic (formerly Hibernia Atlantic) is a 12,200 km private transatlantic submarine cable system in the North Atlantic Ocean, connecting Canada, the United States, Ireland and the United Kingdom. Hibernia Atlantic Submarine Cable System was ready for service on April 8, 2001, with a design capacity of 10.16 Tbps.

In January 2017, GTT completed the acquisition of Hibernia Networks for $USD607 million (initial price was $590 million) , which includes Hibernia Express, Hibernia Atlantic and other assets.

Before the acquisition, Hibernia Networks owns and operates a global network serving more than 100 markets and spanning 25 countries. Hibernia Networks serves customers with unparalleled support, flexibility and service in a variety of industry segments including financial markets, web-centric, media and entertainment, and telecom service providers. Providing enterprise-class and wholesale global connectivity solutions, Hibernia Networks offers secure and diverse optical transport, Ethernet and carrier-grade IP transit services. Hibernia Networks also offers dedicated cloud connectivity, low latency services, DTM and HiberniaCDN for seamless anytime, anywhere content delivery. Hibernia Express, Hibernia Networks’ transatlantic cable, provides the lowest latency connections available between major commercial and financial centers in North America, Europe and beyond. The state-of-the-art cable system garnered two Global Carriers Awards in 2015 — Subsea Project of the Year and Best Subsea Innovation, as well as the Global Telecom Business Innovation Award for 2016.