The 23-year-old soldier, Cedric Cordier, was in uniform patrolling the busy underground corridors where shops and crowded public transport lines converge beneath the famous Arch of La Defense.
Saturday's stabbing came days after a British soldier was hacked to death on a London street in broad daylight in a suspected terrorist attack that has raised fears of potential copycat strikes. However, there was no immediate confirmation of any link between the two attacks.
French police have surveillance video of a suspect taken before and after the attack. There are several security cameras operated by public transport agency RATP and others placed throughout the underground shopping center, according to one police official who spoke on condition of anonymity because he wasn't authorized to discuss terrorism investigations.
The official, who has not seen the videos himself, said investigators describe the suspect as tall. He couldn't provide any other description of the suspect. Police are going over videos to try to identify the suspect, trace his escape route and determine whether he was acting alone, the official said.
Cordier remained hospitalized Sunday, but officials said his throat wound wasn't life-threatening.
The French soldier was on a group patrol as part of a national protection program when he was attacked from behind.
Defense Minister Jean-Yves Le Drian, who visited Cordier at the hospital Saturday evening, said he had been targeted because he was a soldier. Anti-terrorism investigators are leading the hunt for the attacker, but officials have yet to determine whether terrorism is involved, the police official said. Police also questioned witnesses to the attack.
Speaking shortly after the attack while on an official visit to Ethiopia, President Francois Hollande said that while "all hypotheses" will be investigated, there didn't appear to be a link with Wednesday's deadly attack in London.
French security forces have been on heightened alert since their country launched a military intervention in the African nation of Mali in January to regain territory seized by Islamic radicals. British Prime Minister David Cameron was in Paris meeting with Hollande when he first received word of the London attack.
Last year, three French paratroopers were killed by a man police described as a French-born Islamic extremist who then went on to strike a Jewish school in southern France, killing four more people.