Finance Minister Mathias Cormann has moved to quash concerns the Government is selling off its dark fibre communications network that spans 400 buildings across Canberra, but has not ruled out its sale.

Key points: Government network provides 88 government agencies, departments with dark fibre channels for secure communication

Government network provides 88 government agencies, departments with dark fibre channels for secure communication Government assessing whether to sell network

Government assessing whether to sell network Network costs about $8 million a year

The Intra Government Communications Network (ICON) was established in 1991, with five kilometres of cables connecting two Department of Foreign Affairs and Trade buildings in Canberra.

It now provides 88 different government agencies and departments with dark fibre channels for secure communications.

In February, Senator Cormann announced a scoping study to look into the future management and operation of ICON and to assess its likely sale.

No decision on the sale was to be made until the Government received the study, due in the first half of the year.

"What we were considering is whether it was still appropriate for this service to be provided by the Government, given that there is a very broad, very deep and very sophisticated private sector market in place," he said.

Finance department officials told Senate estimates earlier this year there were 1,582 individual cables making up an 882-kilometre ICON network that includes about 160,000 kilometres of fibre.

No desperation to sell ICON, says Cormann

Senator Cormann said the objective was never solely to pursue a sale, but did not dismiss it as an option.

"The objective was to look at how this service is best, most efficiently and most cost-effectively provided. It started off with a very small investment by a government department and it has developed over the last 25 years," Senator Cormann said.

"We think it is important from time to time to ask the question. We have an open mind.

"We were not going into this process with a desperation to sell. We went into this process with a commitment to ensure that the way this network is currently managed is still the most appropriate way."

The high-capacity network costs around $8 million a year to operate.

Senator Cormann said the scoping study had been received and was being considered by Government.

He said opening up a secure network to private interests and the associated national security concerns would form part of any deliberations.

"We think it is always important for Government from time to time to consider whether all of the activities that they are involved in within Government are still appropriately provided by Government or whether there is a more efficient and cost-effective way for particular services to be provided by the private sector," Senator Cormann said.

"This is a secure intra-government communications network. The Government will carefully assess all of the pros and cons of why things have been managed in the past to see what the best way is to manage these things in the future. "

Editor's note: The ABC is one of the agencies which uses the ICON system, linking its Parliament House bureau with its local operations in Canberra. The broadcaster pays a pro rata fee each year to use the system, which is also connected to the Australian National University and the ACT's Emergency Services Agency.