The airplane had undergone checks at the EAS Industries aircraft maintenance center in the French city of Perpignan, near the border with Spain. It was being leased by German charter airline XL Airways and was due to return to service for Air New Zealand next month, officials from those companies said.
The jet plunged into the Mediterranean as it was approaching the Perpignan airport, from which it had taken off on a circular flight an hour earlier, France's civil aviation accident investigation bureau said.
French and German investigators, as well as civil aviation officials and Airbus experts, were heading to the crash site about 20 kilometers (12.5 miles) off the coast, it said.
Two bodies were recovered at sea, the local government said, without identifying the victims.
Five launches, two helicopters and a patrol airplane were searching choppy seas for the other five people who were on board, the regional center for Mediterranean rescue operations said.
"The fuselage has been located. The rescue operations will determine if there are any survivors," said First Officer Sandrine Parro, with the center.
The airplane -- owned by Air New Zealand -- has been operated by XL Airways under a 2006 lease, the German charter company's spokesman Asger Schubert said in Frankfurt. The maintenance checks were part of plans to hand the plane back to its owner.
The crew included two German pilots, Schubert said.
Another pilot and three engineers from Air New Zealand were also on board, as well as an aircraft inspector from the New Zealand Civil Aviation Authority, Air New Zealand's CEO Rob Fyfe said at the company's headquarters in Auckland.
He said the plane had been due to return to Air New Zealand's service next month.
Airbus said the 150-passenger plane had accumulated approximately 7,000 flight hours since its delivery to Air New Zealand in July 2005.
The plane maker said it would be "inappropriate" to speculate on the cause of the crash before the investigation was complete.
Divers were expected to search for the aircraft's black box recorders on Friday, said Bernard Celier, spokesman for the maritime prefecture for the Mediterranean.
Maritime affairs officer Nicolas Renaud said French authorities had been alerted to the accident by the skipper of a sailing boat who said he saw the plane go down. "The plane appears to be in several pieces," Renaud told BFM television.
It was the nearly 29th anniversary of Air New Zealand's worst air disaster. In late November 1979, a passenger plane crashed into Antarctica's Mount Erebus, killing all 259 people on board.