Presidential spokesman Marlin Fitzwater yesterday backed down from President Reagan's assertion on Friday that "I haven't heard a single word that indicated in any of the testimony that laws were broken" in the Iran-contra hearings.

Fitzwater told reporters that Reagan "was reflecting some of the testimony that he had seen on TV, but obviously not every aspect of the case."

Reagan made his remark in a picture-taking sesion Friday with President Omar Bongo of Gabon. Yesterday, when asked about comments by Attorney General Edwin Meese III that some laws may have been broken, Fitzwater described Reagan's comment as a casual one not intended to cover all the hearings.

The spokesman also confirmed that, despite repeated promises to respond after the hearings are over, Reagan does not intend to answer in detail the charges of wrongdoing by his subordinates when he delivers a speech next week.

"Well, there are just so many details and so forth you just can't go through, and, I mean, basically that's what the committee report will do, and independent counsel and others," Fitzwater said. "But it's the overall issues involved that the president wants to address.

"I mean things like dates and times of meetings and places and things like that, you can't go through in a speech," he added.

Reagan has held only two news conferences this year, fewer than at any time in his presidency. He plans to hold none until next month.