Tottenham striker Mido is on the brink of a move to Middlesbrough, Sky Sports News understands.
The Egyptian met with club bosses on Friday and agreed terms on a deal.
He had the first part of his medical and is set to be presented as a Middlesbrough player on Monday if he passes more tests.
However, as a fee has not been agreed between Boro and Spurs, Sunderland have stepped in with an improved offer.
The Black Cats have been linked with Mido in recent weeks and are keen to strengthen their squad further before the end of the month.
Mido had been poised to join Birmingham earlier in the summer but the move collapsed because he was not happy with certain aspects of his contract.