"We still do not know the nationality or the gender of the person rescued," Yemenia Airways' Mohammad al Sumairi said.
But a Comoros police official revealed the survivor was a young child.
The news came amid reports of human remains and debris being spotted by search planes. More than 150 people were on board the jet.
A Yemenia Airways Airbus Two French military planes and a French ship had left the islands of Mayotte and Reunion to search for the Yemenia Airways Airbus A310-300, officials said.
The Comoros foreign ministry said 142 passengers - including three children - and 11 crew were on the flight.
Those on board were nationals from
France and Comoros - sixty-six were reportedly French.
The airbus was flying from Sanaa to Moroni, the capital of the main island of the Comoros archipelago.
Yemenia spokesman Mohammad al Sumairi said: "The weather conditions were rough - strong wind and high seas.
"The wind speed recorded on land at the airport was 61km (38 miles) an hour. There could be other factors."
Relative of a crash victim A United Nations official at the airport said the control tower had received notification the plane was coming in to land, and then lost contact with it.