Australia's National Broadband Network (NBN) and Telstra have finalised a A$11bn deal that allows NBN Co to use Telstra's existing network and infrastructure, a major part of the process that needed Telstra’s co-operation to go ahead.

In a statement to the Australian Stock Exchange, Telstra said the agreement would be for 35 to 40 years and would see Telstra hand over all its broadband services to the NBN over the 10 years it would take for the new network to be completed.

As part of the deal, Telstra has promised to spend A$2bn on upgrading infrastructure and migrating customers to the NBN.

The NBN is a government programme that aims to make high-speed fibre broadband available to 93% of Australian premises. The remainder will be covered through a combination of wireless and satellite solutions, ensuring that all Australians have access to a minimum connection of 12 Megabits per second.

Telstra's CEO David Thodey said the agreement ended the uncertainty surrounding Telstra's possible association with NBN Co and would allow his company to focus on customer service.

The agreement remains subject to approval by the Australian Consumer and Competition Commission as well as shareholder approval, which will go to a vote on 18 October.