The person spoke to The Associated Press on condition of anonymity on Wednesday because the deal has not been announced.
The trade was made after Samuel agreed to restructure his contract to a three-year, $18.5 million deal with Atlanta. His current contract with Philadelphia calls for him to earn $9.9 million in 2012 and $11.4 million in 2013.
Atlanta is expected to send a draft pick to Philadelphia.
The 31-year-old Samuel gives Atlanta a strong trio at cornerback with Dunta Robinson and Brent Grimes under new defensive coordinator Mike Nolan.
Grimes signed his franchise tag tender on Tuesday. Grimes will make $10.262 million this season.
The Falcons have six picks, but no first-round selection in the NFL draft.
Samuel became expendable when the Eagles signed Nnamdi Asomugha and acquired Dominique Rodgers-Cromartie last July, giving them three Pro Bowl cornerbacks. But the team couldn’t find a suitable deal for Samuel, so they kept him and used Rodgers-Cromartie in the nickel spot.
While Asomugha and Rodgers-Cromartie struggled in a new defense and new roles, Samuel was the most consistent of the trio. The outspoken Samuel probably sealed his fate in Philadelphia when he criticized the front office at the trade deadline, saying management was “playing fantasy football with the owner’s money.”
Samuel has 45 career interceptions in nine seasons. He had three interceptions in 14 games last season.
AP Sports Writer Rob Maaddi in Philadelphia contributed to this report.