Crown land held for rail purposes would continue to be owned by New Zealand Railways Corporation and made available for use by KiwiRail.
Finance Minister Bill English and State Owned Enterprises Minister Tony Ryalll said NZ Railways Corporation will continue to hold the 18,000 ha of rail network land, "from which no financial return will be expected''.
The freight, passenger and ferry business along with rolling stock, rail infrastructure and plant and equipment, would be transferred to the new SOE on January 1 next year.
KiwiRail's land and network assets would be written down from about $13.4 billion to about $6.7 billion.
Of that write down, about $4.9 billion would be covered by reversing an existing asset revaluation and the remaining $1.8 billion would be written off.
That $1.8 billion write off will be added to the Government's operating deficit for the current financial year, the ministers said, with the final position to be confirmed over the next few months before the annual accounts were published.
The previous Labour Government bought the rail operation, including rolling stock the ferries and infrastructure from Australia's Toll Holdings for $690 million in 2008.
The Crown already owned the land including the tracks.