Lyttelton Port is struggling to secure insurance to cover natural disasters.
The South Island port has been badly damaged by three major quakes since September last year, which have intermittently disrupted the flow of goods on and off its wharves.
The company's current insurance runs out on Friday afternoon.
Chief executive Peter Davie says the port's cover has in the main been renewed, except for that covering natural disasters, particularly for business interruption and material damage.
Mr Davie says the port has received payments of $35.7 million from its insurers so far.
The damage to the port is thought to be in the hundreds of millions of dollars.