In October 1999, she took over from Rod Deane as Telecom's CEO of the telecommunications business with a $5 billion turnover operating in New Zealand and Australia and listed on the NZX, ASX and NYSE.
During her tenure as CEO Gattung led Telecom through world-changing technology developments and the evolution of the business from a traditional telco to the number one IT provider in New Zealand.
She is NZ Lead for SheEO,[16] a radically redesigned ecosystem that supports, finances, and celebrates female innovators.
[19] In the 2015 New Year Honours, Gattung was appointed a Companion of the New Zealand Order of Merit, for services to business and philanthropy.
[22] In the 2024 King’s Birthday Honours, Gattung was promoted to Dame Companion of the New Zealand Order of Merit, for services to women, governance and philanthropy.