The winning bid means the government raised $259 million from the auction of the spectrum, which became available as a result of the switchover to digital television from analogue.
The government put a minimum reserve price of $198 million for the spectrum, something privately-held 2degrees said was a premium to the $157 million spent clearing the radio waves in the switchover of analogue television to digital and the $119 million valuation attributed to the spectrum by the Treasury.
While some 4G capability is already available on higher MHz spectrum, the 700MHz range is especially well-suited to pushing fast mobile broadband into rural areas because it requires fewer repeater stations to achieve coverage and into densely populated urban settings, such as commercial buildings.
As part of the auction's conditions, the mobile phone operators will have to upgrade existing rural cell sites to 4G capability within five years and continue to expand their coverage. That's to ensure at least 90 per cent of the country has access to a 4G network within five years.
Shares in Telecom increased 0.2 per cent to $2.39 today, and have gained 3.5 per cent this year.
Both 2Degrees and Telecom had expressed concerns that the auction of a fourth round of spectrum would advantage deep-pocketed global player Vodafone.
Telecom's purchase remains subject to clearance by the competition regulator, the Commerce Commission.