Harry Redknapp has wished former England international Andy Cole well after agreeing to cancel the remaining two years of the striker's contract.
Cole, 35, joined Pompey a year ago from Manchester City in a £500,000 move and scored four goals in 22 appearances, many of them as a substitute.
But his exit from Fratton Park was on the cards from the latter stages of last season when he went on loan to Birmingham after complaining he was not getting enough games.
Manager Harry Redknapp said: 'Andy wants to play regularly and we couldn't guarantee that here. Let's hope he can do that wherever he goes next.'
Birmingham did not follow up their loan with a permanent offer despite winning promotion last season and the player's substantial wages are believed to have frightened off Nottingham Forest and Hull.
Relegated Charlton, however, have shown an interest after releasing another veteran striker in Jimmy-Floyd Hasselbaink and selling Darren Bent to Tottenham for around £16million.
Cole, menwhile, has a 'burning ambition' to remain in the Premier League and become a member of the highly exclusive 200 goals club.
He said: 'It is a shame things haven't worked out at Portsmouth. But I'm relieved that it has been sorted out and I can now look forward again.
'I still have a hunger and a burning ambition to score 200 Premier League goals. I have scored goals throughout my career and I now have that added incentive of reaching another personal milestone.
'A number of clubs have shown interest in signing me both from the Premier League and the Championship. I hope to agree terms with a new club before the start of the season.'
In contrast, Kanu's new deal at Fratton Park looks like a formality after his agent revealed the striker is now 'comfortable' with the terms on offer.
It is believed that Kanu, who will miss a large chunk of the season if he plays for Nigeria in the African Nations Cup in January, has agreed a one-year deal with a clause that stipulates he earns another year after playing 16 league games.
Kanu's representative Samuel Okoronkwo admitted: 'It has been protracted, almost like toothache, and Kanu has had to say no to some Spanish teams who were very keen.
'But we managed to strike an agreement with Peter Storrie (Pompey chief executive) and we are comfortable with the terms.'