Britain's The Sun newspaper reported the couple had broken up because Clooney, 51, did not want to commit to Kiebler, 32.
"A story published by a London tabloid, The Sun, concerning George Clooney and Stacy Keibler [is] not true," Clooney's representative told UsMagazine.com. "[The story is a] total fabrication designed to sell newspapers."
'Maze Runner' tops the North American box office
'Maze Runner' brings in $11.3M Friday