The 24-year-old has his contract terminated after failing to report back for pre-season this summer following back-to-back relegations
Sunderland have confirmed Didier Ndong is no longer a Black Cats player after the AWOL midfielder and the club reached terms over an amicable split.
Ndong failed to report back for pre-season training this summer following a second successive relegation, and attempts to sell their club record £13.6million signing before the transfer shut fell flat.
Sunderland served the 24-year-old Gabon international with notice of their intention to terminate his contract last month.
But now an agreement has been reached under which they will be due compensation when he finds a new employer.
A statement said: “Sunderland AFC has reached an agreement with Didier Ndong for his departure on amicable terms. As of 8 October 2018, he is no longer an employee of the club.
“Sunderland AFC has an agreement with the player for a payment by way of compensation upon his signing for a new club.”
Ndong arrived at the Stadium of Light from Lorient in August 2016, as the Black Cats invested heavily in his potential.
But, after a promising start, he struggled to make an impression and, after the club slipped into the Championship at the end of his first campaign, became surplus to requirements under then manager Chris Coleman.
He was sent out on loan to Watford during the second half of last season but did not make a single senior appearance for the Premier League side.
The midfielder was due to report back with the rest of the squad to begin preparations for life in League One, although he and central defender Papy Djilobodji failed to re-appear as their representatives tried, ultimately unsuccessfully, to move them on.
Djilobodji was told his contract would be terminated after he eventually returned last month and underwent fitness tests, and Ndong was served with a similar notice days later after belatedly returning.