Chicago ? The city’s police superintendent said Monday he was stepping down as head of the beleaguered department, but he would not say what role two videotaped beatings involving off-duty officers had in his decision.

Last month, prosecutors filed felony charges against an officer accused of beating a female bartender. Six other officers were removed from street duty after being accused of assaulting four businessmen in a bar.

Superintendent Philip J. Cline took over in November 2003 and had been expected to retire this year. On Monday, he referred to the highly publicized incidents only as “these times of challenge.”

Cline said he will stay on until a replacement was found.

Mayor Richard M. Daley would not say whether he asked Cline to leave; he said Cline had wanted to retire a year ago but stayed at Daley’s request.