New Air France debris found, explosion unlikely

"I am not totally optimistic. We cannot rule out that we will not find the flight recorders," said Paul Louis Arslanian, the head of France's air accident investigation agency.

MINI-SUB ON ITS WAY

France is dispatching a mini-submarine that can explore to a depth of 19,680 feet and will try to locate the Airbus' flight data and voice recorders, which should shed light on the crash.

The recorders are designed to send homing signals for up to 30 days when they hit water, but there is no guarantee they even survived the impact with the sea, Arslanian said.

Brazil is leading its search effort from Fernando de Noronha, a sparsely populated volcanic archipelago and nature reserve off its northeastern coast.

It has mobilized 11 air force planes, four navy vessels with divers and a tanker for the retrieval operation that Jobim said was being carried out in a 120-mile (193-km) radius.

Jorge Amaral, a Brazilian air force colonel, said the long strip of metal found on Wednesday was the biggest piece that search crews had seen so far.

"We are considering this 7-meter piece to be part of the plane, possibly part of the side, a piece of steel. It could be part of the fuselage or the tail," he told reporters.

The French investigation will have its first report ready by the end of the month, and will be led by Alain Bouillard, who took charge of the investigation into the crash of an Air France Concorde in 2000.

France held an ecumenical religious ceremony for relatives and friends of those on the plane at Notre Dame Cathedral in Paris on Wednesday, attended by President Nicolas Sarkozy.

(Additional reporting by Alonso Soto and Rodrigo Viga Gaier in Rio, Laure Bretton and Clement Guillou in Paris; Writing by Stuart Grudgings; editing by Terry Wade and Peter Cooney)