King Louis only joined the Black Cats in the summer on a free transfer from Spurs but the fragile Frenchman has not started a Premier League game for The Mackems.
Martin O'Neill: "We have told Louis is free to speak to other clubs and to leave if he can fix himself up somewhere.
"We have come to an agreement whereby we will cancel the remainder of his contract, shake hands and go our separate ways.
"That said, we are still a bit short in terms of numbers and Louis may stay with us until the end of the month until such time as - hopefully - we have strengthened the squad a little more.
'But we agreed that he could go as early as today, if he wishes to.
"I have heard that there is some interest in South Africa for Louis and it might be of some interest to him."