FRANKFURT (AFP) - Lufthansa said Tuesday it will cancel celebrations marking the German airline's 60th anniversary in the wake of last week's deadly crash of an Airbus jet from its low-cost subsidiary Germanwings.

"Out of respect for the crash victims of flight 4U9525, Lufthansa is cancelling the festivities for the 60th anniversary of the company, which were planned for April 15," the airline said in a statement.

A memorial service for the 150 people who died in last week's crash is being held in Cologne Cathedral on April 17.

And "instead of the planned celebrations, Lufthansa will provide a live broadcast for its employees of the official state ceremony, where the bereaved families and friends will gather to remember the victims," the statement said.

The carrier also said US$300 million (S$413 million) in provisions had been earmarked to cover the damages over the tragedy, as search teams continued to scour the crash site in the French Alps under arduous conditions.

The sum includes financial compensation for the families of the people who died and the cost of the Airbus A320 jet itself, a company spokeswoman told AFP. The current list price of an Airbus A320 jet is US$93.9 million.

The Germanwings flight en route from Barcelona to Duesseldorf crashed on March 24 at a speed of 700 kilometres an hour, instantly killing all 150 people on board.

Investigators analysing voice recorder data say co-pilot Andreas Lubitz apparently locked his captain out of the cockpit and slammed the plane into a French mountainside.

Lufthansa chief executive Carsten Spohr described the accident as the darkest day in the company's history.

Lufthansa has always enjoyed a reputation for technical competence and reliability, but analysts say the crash has dealt a heavy blow to its image.

And in recent months, it has suffered bad press as a result of a long-running industrial dispute with its pilots.

The director of operations at Germanwings, Oliver Wagner, has said that the company would immediately compensate each family with 50,000 euros (S$73,892).

This sum would not be deducted from any final compensation deal, he added.

Lubitz, the co-pilot, was diagnosed as suicidal "several years ago", before he became a pilot, but had appeared more stable of late, German prosecutors said Monday.

Doctors had recently found no sign he intended to hurt himself or others, said Ralf Herrenbrueck, spokesman for the prosecutor's office in the western city of Duesseldorf.

However, he was receiving treatment from neurologists and psychiatrists who had signed him off sick from work a number of times, including the day of the crash.

Ripped up sick notes were found in a flat used by Lubitz, which authorities believe indicates that the 27-year-old was trying to hide his illness from his employer for fear of losing his job.

MISSING 'BLACK BOX'

Meanwhile investigators resumed their grim search through the wreckage and hundreds of body parts in the French Alps using a new service road built to the remote crash site.

Three trucks set off from the dropzone in the town of Seynes-les-Alpes early in the morning after a hectic 48-hour road-building operation to ease access to the mountainside.

"It means we can work work faster, later and bring back more items," said one police officer.

Trucks now take 45 minutes to reach the base of the rocky slope where debris remains spread across some two hectares, while two helicopters hover overhead to check for pieces that may have been flung further.

Somewhere in there lies the second "black box" recorder, which gathered technical data on the flight, and has yet to be found.

'SYSTEMIC WEAKNESSES'

Forensic teams have isolated almost 80 distinct DNA strands from the shattered aircraft and have described the grim task as "unprecedented" given the tricky mountain terrain and the speed at which the plane smashed into the rock.

French investigators said they would now concentrate on "the systemic weaknesses" that might have caused the disaster, including the logic of locking cockpit doors from the inside, which was introduced after the suicide hijackings of September 11, 2001, in the United States to stop terrorist attacks.

It said it would also look into procedures for detecting "specific psychologic profiles" in pilots after indications that Lubitz may have suffered from depression.