French officials have found one of the two black boxes of a German passenger plane that crashed in southern France with 150 people on board, while a joint international probe into the cause of the accident is underway.

The black box is used for recording conversations in the cockpit of the ill-fated plane, an Airbus 320 of Germanwings, a low-cost airline owned by German flag carrier Lufthansa, France's BFMTV reported.

The jetliner was on its way from Barcelona, Spain, to the German city of Duesseldorf when it crashed early on Tuesday. French President Francois Hollande said there might be no survivors among the 144 passengers and six crew members.

The BFMTV report said the other black box, which is used for storing flight data, has not yet been retrieved, adding that search and rescue operations have been currently suspended but will resume on Wednesday morning.

French Interior Minister Bernard Cazeneuve, who was at the site of the crash, said the flight recorder would be transferred to investigative services.

"The black box will be analyzed in the coming hours to allow the investigation to move quickly," he said, noting that measures had been taken to prepare the crash zone for the investigation so it could take place under the best conditions.

Aircraft on ground mode

The Germanwings plane, which left Barcelona on Tuesday morning for Duesseldorf airport, started to descent shortly after reaching its cruising altitude of 38 000 feet and crashed in a snow covered area in the southern French Alps.

Causes of the crash remained unclear. The German Federal Bureau of Aircraft Accident Investigation (BFU) has sent investigators to France and a joint investigation by France, Germany and Spain is opened to find out the causes of the tragedy. A group of experts from Lufthansa, Germanwings and Airbus were also dispatched on Tuesday to the crash site.

A spokesperson for Lufthansa told Xinhua that the plane had a technical problem with its nose landing door and was prevented from flying in Duesseldorf airport on Monday.

She thus confirmed a previous report from German Der Spiegel magazine that the plane was in "Aircraft on ground" (AOG) mode one day before its crash.

The problem was then "completely solved" and left "no security risks," stressed the spokesperson. The plane returned to normal operation on Monday morning.

She declined to confirm another report that several pilots at Germanwings refused to fly planes with the same model as the crashed A320 aircraft, only saying that some pilots could not take up their position due to "personal reasons" which her company could understand.

Earlier on Tuesday, Germanwings chief executive Thomas Winkelmann told reporters that the crashed plane received its last "routine check" on Monday in Duesseldorf by Lufthansa's technicians.