Reds' boss Joe Kinnear said: "I would like to thank Nicky for all his efforts during his time with us a wish him well for the future,"
His Leeds team mates beat Manchester City 2-1 on Monday night with another former Forest loanee, Stephen McPhail, scoring the first goal from a free-kick.
Meanwhile, Brynjar Gunnarsson has joined Stoke City permanently until the end of the season instead of an initial one month's loan.