Sen. George Mitchell, D-Maine, a member of the Iran-Contra panel, says Oliver North probably will never face a jury because President Reagan will pardon his former White House aide to avoid a trial.

But Mitchell's Republican colleague from Maine, Sen. William Cohen, also a member of the congressional committee that investigated the scandal last year, said he does not detect any administration effort to prevent North's trial, despite the national security concerns arising in the court case against the chief operative in the Iran-Contra affair.Mitchell and Cohen discussed last year's congressional investigation and the criminal prosecution of North in an interview last week to promote their book, "Men of Zeal: A Candid Inside Story of the Iran-Contra Hearings," to be published Thursday.

Written in an intense 12 weeks late last year - in longhand, because the senators say they cannot type - "Men of Zeal" examines the summerlong spectacle of the congressional hearings into the scandal and, Cohen said, "This book is as critical about us than anything else."

"We have not been apologists for the committee," Mitchell said. "We have been very candid in our criticism of what the committee did. But given the context and given the constraints under which we operated, I think we got most of the information, although we clearly did not answer every question."

Cohen, Mitchell and 24 other members of the House and Senate on the select committees spent most of 1987 investigating the U.S. arms sales to Iran and the diversion of sales profits to the Nicaraguan Contra rebels.

A key error the committees made, the senators said, was underestimating the power of television.

"The hearings . . . offer the classic demonstration of the fact that television transforms an event even as it reports it," Mitchell said. "One may debate whether that is good or bad, but it's reality. We did not sufficiently take it into account."