And the Super League club confirmed they have also disciplined the back-row forward who has been suspended for more than a month.
The suspension came just days after he earned rave reviews for his performances for England in the Test series against New Zealand.
Ferres, 29, who has played 89 games for the Giants and scored 35 tries, was suspended and has not been allowed to train with the rest of the squad.
He posted a picture on his own twitter page showing him training in a gym.
A club spokesman said: “Huddersfield Giants have concluded the investigation into the conduct away from the field which led to the suspension of Brett Ferres.
“That suspension has been lifted and Mr Ferres disciplined in line with company policy.
“Mr Ferres has also been transfer listed.
“The club will be making no further comment at this stage.”
In May this year the back row forward rejected advances from the NRL to remain with Huddersfield.
The England international committed to the Giants future by signing an extension to his contract to tie him to the club until the end of 2019.
Both Salford and Hull FC have been rumoured to be interested in the star.