Porto have agreed to sell highly-rated duo Joao Moutinho and James Rodriguez to Monaco for £60million.
Ross County manager Derek Adams has extended his contract until the summer of 2016.
Rigg joined the Barclays Premier League strugglers from Manchester City last season to renew his partnership with then Rangers boss Mark Hughes.
But following Harry Redknapp's appointment as Hughes' successor last month the club have opted for a further change.
They confirmed Rigg's departure in a brief statement on their website that said: "Queens Park Rangers Football Club can confirm that it has been agreed that Mike Rigg will leave his position at Loftus Road."