The pod of 77 whales became stranded after swimming too close to the shore near Marsden Point on the east coast of New Zealand's northland region, said Conservation Department spokesman Bryce Lomis.
Boats were patrolling near the 40 refloated whales to encourage them to return to sea rather than beach themselves again.
"At the moment it's important that we continue to assess the situation and will ask for more assistance if and when it's required," Lomis said.

Copyright AFP (Agence France-Presse), 2006