Aston Villa boss Paul Lambert has defended his decision to send striker Darren Bent out on loan to Brighton.
Tranmere chairman Mark Palios claims to have turned down the chance to sign Ched Evans.
Seaborne has won three and drawn one of the four matches he has played in since making the temporary move to The Valley.
The 25-year-old was forced to sit out the final match of his original loan spell, last Saturday's 2-2 draw against Brighton.
But Seaborne will get the chance to extend his unbeaten run in the Charlton team after a fresh deal was struck.