The termination will be effective immediately and the Cowboys will seek to add a player to their roster for season 2014.
CEO Peter Jourdain said while it was unfortunate that Ulugia would no longer be with the Cowboys, continual conduct breaches, which came despite the player receiving professional guidance from inside and outside the club, could no longer be tolerated.
“We will not be going into details of the breaches,” Mr Jourdain said.
“Wayne is aware he has not met the standards required and despite efforts from both he and the club to get him on the right track, the problems continue to occur.
“There’s no doubt he has enormous talent as a footballer and we have seen that develop through his time at the Cowboys, but we have a code of conduct that has to be followed.
“If Wayne wishes, we will continue to help him through this period of his life even though he will no longer be a part of our NRL squad.
“We hope that at some stage in the future he can make a success of his rugby league career.”