The disaster is the deadliest avalanche to strike the French Alps in a decade.
At least one Swiss, a German and two Spaniards were among those killed in an avalanche on Mont Maudit, the Mont Blanc massif's third-highest peak.
Four more climbers -- believed to be two Britons and two Spaniards -- were still missing.
An avalanche swept over a group of foreign climbers in the French Alps on Thursday, killing at least nine people in the deadliest such disaster in the region in a decade.
Most of the dead found after the early morning avalanche on Mont Maudit, which translates as "Cursed Mountain", were Europeans, officials said.
Among the dead were at least one Swiss, a German and two Spaniards, local prefect Philippe de Rumigny told AFP. Officials had earlier reported two Swiss and two Germans dead.
The bodies of three more victims, believed to be those of British climbers earlier reported missing, were also found during rescue efforts, according to preliminary information.
Four more climbers -- believed to be two Britons and two Spaniards -- were still missing, officials said.
Efforts were continuing to track down the missing climbers on the mountain in the Mont Blanc massif at a height of more than 4,000 metres (13,100 feet), with Italian rescuers brought in to assist France's PGHM high-mountain group.
Nine more climbers were lightly injured and treated at a local hospital.
Interior Minister Manuel Valls said he was heading to the scene to oversee operations.
"Searches are still underway to find the missing," he said in a statement. "The interior minister wants to assure the families of his deep sympathy and full support."
One of the injured sounded the alert at around 0325 GMT after the avalanche on Mont Maudit, the massif's third-highest peak, rising to an altitude of 4,465 metres (14,650 feet), and considered one of the more difficult paths to climbing Mont Blanc.
Rumigny said it was believed that a "40-centimetre (16-inch) sheet came loose" from the mountainside, prompting the avalanche.
Francois said it was believed a climber had caused the sheet of snow and ice to break off.
Weather service Meteo France told AFP there were strong winds in the area on Thursday, reaching up 70 kilometres (43 miles) per hour.
It is the deadliest climbing disaster in at least a decade in France.
In August 2008, eight climbers -- four Germans, three Swiss and an Austrian guide -- were swept away after blocks of ice broke off Mont Blanc du Tacul, prompting an avalanche.
Thousands of tourists flock to the French Alps every year for sports including mountain climbing and skiing, but every year some fall victim to accidents.
A Norwegian cross-country skier died in April after being caught up in an avalanche on Mont Blanc, only about a month after a Canadian skier died after plunging into a 20-metre (65-foot) crevice on the mountain.
Rescue workers are often called in to assist stranded climbers or skiers.