No sign of human remains have been spotted, and Air France has told families that the jetliner broke apart, killing all 228 people on board.

Two buoys - standard emergency equipment on planes - also were recovered from the Atlantic Ocean about 550 kilometers northeast of Brazil's northern Fernando de Noronha islands by the helicopter crew, which was working off a Brazilian navy ship.

Air France's CEO Pierre-Henri Gourgeon told family members at a private meeting that the Airbus A330 disintegrated, either in the air or when it slammed into the ocean and there were no survivors, according to Guillaume Denoix de Saint-Marc, a grief counselor who was asked by Paris prosecutors to help counsel relatives.

Seas were calm Thursday with periodic rain as ships converged on three debris sites to recover wreckage, but French military spokesman Christophe Prazuck said extreme cloudiness' prevented US satellites from helping.

'The clock is ticking on finding debris before they spread out and before they sink or disappear,' Mr Prazuck said. 'That's the priority now, the next step will be to look for the black boxes.'

French planes and a US Navy P-3C Orion surveillance plane joined Brazil's Air Force, whose pilots guided Navy ships to debris areas across a search zone of 6,000 square kilometers, said Brazil Air Force Gen Ramon Borges Cardoso. He said collection of debris could begin Thursday. No bodies or body parts were seen.

Floating debris spotted so far includes a seven-meter chunk of plane, an airline seat, an oil slick and several large brown and yellow pieces that Gen Cardoso said probably came from inside the plane.

Brazil's Defence Minister Nelson Jobim said debris had spread more than 230 kilometers apart in currents roughly 640 kilometers northeast of the Fernando de Noronha islands off Brazil's northern coast, where the ocean floor drops as low as 7,000 meters below sea level. -- AP