CHICAGO -- Big Ten Commissioner Jim Delany said Thursday he'll consider a number of measures, including instant replay, to help football officials do their job. But he won't let anyone question their integrity.

"And where I draw the line,'' the commissioner said, "is when somebody begins imputing bad intentions.''

Delany's remarks came in response to mounting criticism of league officials touched off by Penn State coach Joe Paterno.

After the Nittany Lions' overtime loss at Michigan last weekend -- their second controversial overtime loss to a conference rival -- Penn State athletic director Tim Curley asked Delany for a comprehensive review of the league's officiating program.

The commissioner replied in a brief statement that the league would review any specific grievances that Penn State submitted. But at a news conference the next day, Paterno suggested that because the officiating crew included three Michigan residents, favoritism may have colored some decisions.

That prompted a longer response from Delany.

"If there were mistakes, I have no evidence or belief they are anything other than that. If I did, I'd have a whole other set of concerns,'' he said during a telephone interview from the league's suburban Chicago office.

The commissioner said preliminary research by the league found "four or five mistakes every game, pretty much the average for the 13 years I've been here.''

The league's officiating problems began with a Sept. 21 game between Purdue and nonconference opponent Wake Forest. A review prompted the conference to dismiss four league officials who worked that game.

The following week, Penn State lost to Iowa. Two late calls in that game so angered Paterno that after the final whistle, the 75-year-old coach sprinted down the sideline and grabbed an official by the jersey to complain.

Instead of disciplining Paterno, Delany said the episode prompted him to look at his officials.

"Joe Paterno has been a leader, both inside and outside the game, and over the course of decades he's come to represent our best values. So if he loses confidence in the system, even temporarily, we've lost a lot. And he's not the only one to suggest we have a problem,'' Delany said.

Because of Paterno's reputation for fairness, his decision to speak up emboldened a few of his colleagues.

Asked if he agreed with Penn State's call for a review, Purdue coach Joe Tiller replied, "Absolutely. Unequivocally. Yes.''

Michigan's Lloyd Carr and Illinois' Ron Turner recently echoed those sentiments, with Turner, long a proponent of instant replay, talking about even more sweeping changes.

Delany said everything about the officiating program will be open for discussion -- after the season.

"At the moment, we're going to have to live with the handful of mistakes that happen in every game. If they came earlier in games or if the outcomes were different, this might not even be a topic. ...

"The reality is everybody makes mistakes -- coaches, players and officials. We'd do anything to reduce the bad calls to zero, but I don't know if we can.

"And look, if some form of replay would cut that down to two a game, and there's support from coaches and administrators, we'd be silly not to look at it,'' he said.