In addition to the U.S. citizens, the passengers included 61 French citizens, 58 Brazilians, 26 Germans, nine Chinese and nine Italians. The group included seven children, a baby, 126 men and 82 women.
Michael Harris, a geologist working in Brazil for natural gas and oil producer Devon Energy, had been transferred from Houston to Brazil in 2008.
"We are extremely saddened by this development and trying to monitor the situation as it unfolds," said Devon Energy spokesman Tony Thornton in a statement. "We're doing what we can to help the family at this time."
The flight had been expected to land in Paris at 5:15 a.m. ET after leaving Rio around 6 p.m. Sunday night.
The Brazilian air force said in a statement that it had been anticipating radio contact with the plane when it was still over northeast Brazil, but when it received no radio communication, Brazilian air traffic control contacted air traffic control in Dakar, Senegal. There was no mayday call and no nearby planes received a call for help on the international emergency frequency.
On Monday night a crew from TAM, Brazil's largest air carrier, said it saw orange spots on the ocean while flying over the same general area as the Air France Flight 447.
ABC News' Renata Araujo, Sonia Gallego, Joe Goldman, Christel Kucharz, Luis Martinez, Phoebe Natanson, Gabriel O'Rorke, Samira Parkinson-Smith, Kirit Radia and Christophe Schpoliansky, Reuters and The Associated Press contributed to this report.