The 31-year-old's Addicks career has been blighted by injury during the past two years, and the Premiership strugglers have opted not to offer Pringle a fresh deal.
Pringle initially joined Charlton in January 1999 on loan from Benfica before making his move permanent.
But he has started a solitary game for Charlton during the past two seasons and linked up with Grimsby Town on loan in February.
In only his second game for The Mariners, Pringle broke his leg and he has been battling to regain fitness in the ensuing period.
His contract at The Valley expired at the end of the last campaign but Charlton chief Alan Curbishley handed him a short-term deal.
That has now expired, and though Pringle is still training with the club, he is free to search for pastures new.