Russian officials are reported to be finalising a $200m insurance policy against any damage its Mir space station may cause when it plunges to Earth this month.

The news came as the date for the final ditching of the station slipped back to 20 March.

According to Russian sources, three firms will provide insurance against the chance of any fragments of the platform falling on to populated areas.

Any remnants of the 15-year-old space station that do not burn up in the Earth's atmosphere on re-entry should fall into the sea around 3,000 km (1,850 miles) east of the southern tip of New Zealand.

The New Zealand Government has set up an expert committee to deal with any risks to ships and planes in the area.

Fuel in reserve

Mir is due to make its final descent to Earth on 20 March, a few days later than planned.

Demonstrators in Moscow want Mir to stay aloft

The ditching of the station is being delayed to save fuel, Russian officials said on Wednesday.

Allowing the station to move closer to Earth before giving it a final push will mean that there will be more fuel in reserve in the rocket attached to the platform.

Mir is currently orbiting around 255 km (158 miles) above the Earth and will now be brought down when it reaches 220 km (137 miles), the officials explained.

Warning shipping

New Zealand's Prime Minister, Helen Clark, announced a special team on Wednesday to deal with the consequences of the Mir space station's return to Earth.

The authorities in New Zealand will have to warn shipping and aircraft as the ageing former Soviet space station re-enters the Earth's atmosphere.

"Precise information on the location and date will not be available until a day or two beforehand," Helen Clark said.

"The planned final orbit will take Mir on a trajectory over Japan and Fiji, then towards Argentina if it overshoots.

"There are no radioactive, biological, chemical or other dangerous materials on board, so in that respect it poses no danger.

"While we are confident that the Mir space station poses no risk to New Zealand, the expert committee will continue to closely assess all the available information," she said.