The 28-year-old United States international midfielder spent the recent MLS??season on loan to Philadelphia, making 31 appearances and scoring three goals??before sealing a place in the MLS All-Star team.
Because Edu had joined Philadelphia ahead of the start of the 2014 season on loan, a deal??had to be worked between the Union and Stoke in order for Edu to return to Philadelphia.
The switch to the Union brings to an end his nightmare time with Stoke where he made a single substitute appearance, lasting nine minutes, following a move from Rangers in August 2012.
Union technical director Chris Albright said: “Mo is an extremely important player to our organisation??and we???re excited that he will be in Philadelphia for the foreseeable future.
“We look forward to him helping lead us toward building a winning team.”
Edu added: “I couldn???t be happier to permanently return to Philadelphia and to play in front of our great??fans,” said Edu. “I believe in this team???s future and am excited to be an integral part of that.”