The buildings - one condemned and apparently vacant, the other containing apartments - collapsed at about 9am on Monday.
A spokesman for the Marseille Firefighters told The Associated Press on Tuesday that a man's body was recovered, in addition to the bodies of another man and a woman they found earlier.
Authorities said they were looking into what caused the collapse of the buildings, described by residents of the area as dilapidated and in need of fix.
Rescue teams are searching for survivors amid rubble after two buildings collapsed in Marseille, France, on Monday morning.
Arriving at the site Tuesday, Interior Minister Christophe Castaner said "air pockets" under the debris meant there's "hope to locate and find someone that can be saved".
The body of the third victim was found among the wreckage after the same day found the bodies of the other men and women, said the representative of the fire Department of Marseilles. It was not immediately clear why they collapsed, or how many people the apartment building housed.
"We still have hope, even if that hope is fading".
Only one of the buildings, number 65, was occupied. The disaster, he added, was "100 percent the fault of city hall".
"The most important is saving lives", Castaner said at the scene.
"She was a great girl, she used to come and study at the bar", he said, without giving his name.
Abdou Ali, 34, came in search of his mother after she did not come to collect her youngest son from school on Monday afternoon. "It could have been me", she said.
Recall that on 5 November it became known that two houses collapsed in Marseille.
But the incident - rare in a major Western city - has already sparked a political row over the quality of housing available to Marseille's poorest residents.
Marseille authorities began a vast upgrade plan for the city centre in 2011. In 2011 the local authorities began a plan to renovate the city centre, but a 2015 government report suggested that 100,000 Marseille residents were living in housing unsafe to their health or security.
Djaffar Nour, who was shopping down the street, said the collapse had happened in "a matter of seconds".