Kraftwerker
Formerly RedAddict
He says "Re-negotiation", which suggests he means with Newcastle, with whom the original negotiation took place. It wouldn't seem to refer to some new negotiation between Spurs and some new club that Spurs might sell to. And in any case, what you've said would still leave Newcastle relying on this new club (and not Spurs) to pay the remainder to them.
All in all, it doesn't seem like a very normal deal to me.
Nope I meant Spurs would negotiate with Newcastle so that the buying club could pay whatever was owed in whatever instalments suit them.
Let's say Sissoko flops massively and Spurs are desperate to get rid next summer. His value will likely be around £10m.
At that point Spurs will have paid £12m to Newcastle. Newcastle aren't just going to say forget the rest of the £18m. Spurs will cough it up or the buying club will The terms of the installments will probably just change.