The club are unbeaten at home this season but that was seemingly not enough to satisfy the grand ambitions of Swiss-based Middle East owners Munto Finance, who took over at Meadow Lane in the summer.
Rumours had linked director of football Sven-Goran Eriksson with an exit amid claims he had become frustrated with the uncertainty over the club's ownership, but it was McParland who departed following a meeting with executive chairman Peter Trembling.
A statement from Trembling on the club's official website read: "Everyone at the football club is genuinely sorry to part company with Ian.
"We are all aware of the commitment and service he has given to the club, both as a player and a manager.
"It is an inescapable fact that the hopes and ambitions of the football club have been totally transformed in the past few months.
"Up until this summer the club's principal objectives had been financial survival and maintaining its status in the Football League.
"Now we have a five-year project to deliver sustainable success to the club and our focus is to reach the Championship and beyond.
"Ian has been manager of the football club for the past two years and during that time his passion and commitment has never been in doubt.
"However, as a board of directors, for footballing reasons we felt a need to make a change to the current situation."
County have yet to announce who will take charge of first-team affairs for Saturday's trip to fellow high-fliers Rotherham.
Speculation is already rife regarding McParland's successor, with the likes of Eriksson, Roberto Mancini, David Platt and Alan Curbishley among those linked with the post.
Trembling's statement continued: "Appointing a new football manager is arguably one of the single most important decisions that a football club can take, regardless of whether they are in the Premier League or in non-league football.
"Our next appointment is going to be extremely vital to the project we are endeavouring to deliver here.
"We fully understand and appreciate there will be considerable debate about the identity of the new appointment.
"What I can say is that we will take the appropriate amount of time to ensure we make the right appointment. This will be done to our own time schedule.
"As we would all expect, our director of football Sven-Goran Eriksson will be responsible for this appointment.
"It is our intention to announce within the next 24 hours who we will be appointing as caretaker manager to prepare the team for Saturday's game against Rotherham.
"Beyond that we cannot make any further comment at this stage."
County are still waiting for their takeover to be ratified by the Football League.
Trembling stated he was "encouraged" by the meeting the club had with the league in London last week and, following further discussions in the last 48 hours, he expects an imminent and positive outcome.
"We have now provided the Football League with the additional information they requested and we hope to hear from them very shortly," added Trembling in a separate statement.
"The club is encouraged by the free and frank spirit of its continuing dialogue with the Football League, as part of which it is happy to make clear that it has severed all ongoing connections with Mr Russell King.
"Mr King's involvement with the club was limited to a short period following the recent acquisition and pending the new board being put in place.
"All future decisions affecting the club are now squarely and exclusively in the hands of the board members."