Press Association Sport understands the 30-year-old Argentina international has not submitted a formal transfer request, but has indicated his desire to return to South America for personal reasons, although the club was not commenting on the matter today.
Coloccini signed a four-year contract extension in March last year as Pardew tied up one of his most influential players on a long-term deal.
However, he has struggled to reproduce his stunning form of last season this time around with Newcastle underperforming as a team, while Pardew acknowledged there had been a difference of opinion between the two as the busy Christmas programme approached.
The current issue is understood not to be football-related and while delicate negotiations are under way, the former Deportivo la Coruna player's future remains uncertain ahead of his anticipated return to the squad for tomorrow's Barclays Premier League trip to Norwich.
Rumours of Coloccini's unrest first surfaced when his father Osvaldo revealed Argentinian club San Lorenzo were keen to recruit him, but the latest development has come at a time when Newcastle least need it after last Saturday's 2-0 FA Cup third-round defeat at Brighton capped a miserable run of form.
Pardew said: "It was a difficult situation. It was a really horrible day for the players and fans and more importantly the staff, but we have to lick our wounds.
"We are much stronger this week and that is much better for us."