A rat is suspected as being one of two culprits who paralysed the country's telecoms network yesterday, closing the Stock Exchange and stopping shoppers using Eftpos machines.

The second was a Powerco contractor who "nicked" a fibre optic cable near Waverley in South Taranaki while drilling a hole to replace a power pole at 10.40am.
The "one in a million" coincidence of damage to two fibre optic cables affected more than 100,000 Telecom customers from 10.48am until 3.18pm.

The greatest disruption was in Wellington and Taranaki. Services were also lost in Auckland, Palmerston North and in the South Island.

Trading on the Stock Exchange was brought to a halt from 11.01am until 4pm. The exchange stayed open for an extra 30 minutes until 5.30pm.

Eftpos disruption hurt shoppers and retailers. The online auction site TradeMe reported a significant reduction in traffic between 11am and 3pm.

Air travellers experienced delays of 25 minutes or more when the loss of internet and email forced Air NZ to manually check-in passengers.

Telecom spokesman John Goulter said it was possible a rat was the cause of the broken fibre optic cable on a railway bridge, about 5km north of Upper Hutt. Rodent damage was a problem inside the 10cm steel ducts that carry fibre optic cables, he said.

"We haven't ruled it [a rat] out."

Another possible cause was the cable coming adrift and being carried away in the river.

Mr Goulter said the odds of the two main fibre optic cables running up the west and east sides of the North Island failing at the same time were about one in a million.

Telecommunications Users Association chief executive Ernie Newman said Telecom rated well for network and service reliability and he did not see it as a sign of a trend.

However, brokers were annoyed, especially as it was the second Telecom fault in a week to halt trading.

One broker said stoppages added to uncertainty for the market and investors "hate uncertainty".

Stock Exchange spokeswoman Rowan MacRae would not be drawn into detail about compensation.

"Our key thing has been to focus on getting the market back up and running as quick as we can and to let international markets know what has happened here today. We will worry about the other issues later."

Retailers Association Auckland regional manager Russell Sinclair said given that many people no longer carried cash, "It certainly bites" when Eftpos went down.

Communications Minister David Cunliffe said "getting two accidents of this type at the same time is a freak occurrence".

Last week about 2000 Telecom customers were affected when a contractor accidentally cut a cable between Waihi and Whangamata. The eastern side of the Coromandel Peninsula and Great Barrier Island were affected.

Off the hook

* Air New Zealand: Manual check-ins delay flights south of Hamilton.

* Bank of New Zealand: Three money machines down in Taranaki and processing problems in Stratford, Hawera and Waipukurau.

* MetService: Incoming and outgoing weather data disrupted.

* Inland Revenue: Delays to filing monthly schedules by some businesses.

* TradeMe: Between one-third and half of 200,000 members unable to buy or sell for four hours.