Winger Jerome Thomas has agreed a one-year contract with Portsmouth, who have decided to make his loan move from Charlton permanent.
Pompey will pay Charlton an undisclosed fee if the 25-year-old, who joined last week and made his debut as a substitute in the 4-0 Barclays Premier League defeat at Chelsea, makes a specified number of appearances.
Chief executive Peter Storrie said: 'Jerome could have been recalled by Charlton in January under the terms of his loan, but that's no longer a factor now.'
Under Premier League rules, clubs are allowed only four loans per season - and Portsmouth already have striker Ben Sahar on a six-month stay from Chelsea.
