WASHINGTON - Political appointees in NASA's public affairs office "compromised" information on climate-change science for political advantage over a two-year period, an audit by the agency's inspector general found.

Communications issued between late 2004 and early 2006 "reduced, marginalized or mischaracterized global warming research made available to the general public," the auditors wrote in a statement released yesterday.

The inquiry followed allegations by James Hansen, the top climate scientist at the National Aeronautics and Space Administration, that public affairs officials prevented him from speaking to the media in December 2005, according to the audit. Hansen in 1981 warned global-warming pollution was heating the planet faster than forecast, and he has joined environmental groups in calling for a faster transition to cleaner energy sources such as wind.

"The core issue of how our government in general, and NASA in particular, continues to manage the important issue of climate change information is worthy of careful consideration by both the executive and legislative branches of government," the auditors wrote.

Kristin Scuderi, spokeswoman with the White House Office of Science and Technology Policy, said the agency has no comment on the report's findings.

Fourteen U.S. senators co-signed a Sept. 29, 2006, letter to NASA's inspector general requesting the probe into allegations of "political interference" with the work of the space agency's scientists.

Investigators interviewed 59 witnesses, including present and former NASA scientists, public affairs officials and senior managers, and reviewed more than 10,000 pages of documents and congressional testimony, according to the audit.

The political appointees in public affairs denied influencing news releases, claiming instead many were "poorly written or too technical in nature for meaningful broad public dissemination." The dispute didn't extend to global warming research distributed to the scientific community, including journals and conferences.

Keith Sefton, deputy general counsel to NASA, said in a written response included with the audit that the findings weren't supported by evidence.

"The report, by failing to distinguish between substantiated problems and mere speculation and allegations, contributes little to the understanding or issue resolution," Sefton wrote. "The legitimate conclusions arising from these circumstances are those that NASA has already acknowledged, and has long since fixed."