A league source told ESPN NFL Insider Adam Schefter that Avant's new deal is worth up to $18 million and includes $8 million guaranteed.
Avant was a restricted free agent. He had a career-best 41 receptions for 587 yards and three touchdowns last season as Philadelphia's slot receiver.
"Jason Avant has developed into one of our most dependable and productive players on offense," Eagles coach Andy Reid said Monday in a news release. "He's physical, he's tough and he has the respect of all of his teammates."
Selected in the fourth round in 2006, Avant has 103 catches and eight TDs in four seasons. He has a knack for making clutch catches. Avant has 37 receptions on third down, including 32 that have resulted in first downs.
"He's an extremely hard worker, yet he's very humble," general manager Howie Roseman said. "Plus, he's a extremely tough competitor on the field. I'm glad he'll be a Philadelphia Eagle for the long haul."
Information from The Associated Press was used in this report.