An American scientist accused of manipulating research findings on climate science was cleared of that charge by his university on Thursday, the latest in a string of reports to find little substance in the allegations known as Climategate.

An investigative panel at Pennsylvania State University, weighing the question of whether the scientist, Michael E. Mann, had “seriously deviated from accepted practices within the academic community for proposing, conducting or reporting research or other scholarly activities,” declared that he had not.

Dr. Mann said he was gratified by the findings, the second report from Penn State to clear him. An earlier report had exonerated him of related charges that he suppressed or falsified data, destroyed e-mail and misused confidential information.

The new report did criticize him on a minor point, saying that he had occasionally forwarded to colleagues copies of unpublished manuscripts without the explicit permission of their authors.