Sold to Leeds for a few hundred thousand pounds in 2010 McCormack was said today to be the subject of a £4m bid from his former employers.
Since arriving at Leeds McCormack has scored 43 league goals in 100 starts and he wants to stay there.
"I am really happy at Leeds and look forward to staying at the club," he said.
"I'm club captain and I look forward to continue playing at the club under Brian McDermott for the rest of the season."
Cardiff are also reported to have made a bid for Reading striker Adam Le Fondre.