Spark, Vodafone and Telstra have confirmed they will spend $US70 million ($A75.74 million) building a new trans-Tasman telecommunications cable next year.

The 2300km submarine cable – dubbed the Tasman Global Access Cable – will help the companies cope with the increase in internet traffic between New Zealand and Australia.

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The cable – two fibre pairs with total capacity of 20 terabits per second – will run between Raglan on Waikato’s west coast and Oxford Falls, Sydney.

The chief executives of the three companies said the partnership was a great outcome.

Alcatel-Lucent won the tender for the cable-laying job and the cable is expected to be up and running by mid-2016.

New Zealand is already connected to the rest of the world by the Southern Cross cable, which goes through Hawaii and Sydney, and the Tasman 2 cable, which already links Auckland with Sydney.