It's understood King, who signed his previous contract before Euro 2004 securing wages of £30k a week could now earn up to £50k a week, making him one of the club's top earners.
Assistant head coach Chris Hughton told The Times newspaper: "Ledley is a strong defender and has very good quality on the ball.
"He is one of the quickest defenders with a very good stride. He is a very consistent player. I see him up there with the best."