About a third of the heavy fuel oil inside a submerged tank on the grounded container ship Rena has now been transferred to a bunker barge.
Maritime New Zealand says that as of 6am Friday 116 tonnes of oil had been transferred to the barge Awanuia.
The authority's salvage adviser, Jon Walker, says the pumping rate is up to about four tonnes an hour.
He says salvors have put an extra pump in the system and will instal two additional connections known as hot taps to further boost the flow.
Mr Walker says the pumping rate will slow down once there's less oil in the tank.
The lubricant storage tanks on board the Rena are now empty and salvors are stripping the engine-room of smaller clusters of oil.
