WASHINGTON — A federal judge ruled yesterday that a White House office that has records about millions of possibly missing e-mails does not have to make them public.

U.S. District Judge Colleen Kollar-Kotelly says the Office of Administration is not subject to the Freedom of Information Act, enabling the White House to maintain the secrecy of a lengthy internal paper trail about its problem-plagued e-mail system.

The decision came in a lawsuit filed against the administration by Citizens for Responsibility and Ethics in Washington, a private group that has been trying to find out the extent of the White House’s e-mail problems for more than a year.

The functions of the Office of Administration “are strictly administrative,” Judge Kollar-Kotelly ruled.

She said the Office of Administration has no authority over others in the executive branch and that the office is exclusively dedicated to providing services to the Executive Office of the president.

Since its creation in 1978, the Office of Administration has responded to FOIA requests. But the Bush White House reversed that policy in August 2007 in the lawsuit filed by CREW.

Judge Kollar-Kotelly’s decision closes off one avenue of inquiry because while CREW is appealing, time is running out, with just seven months remaining in office for the Bush administration.

Still, the White House’s legal problems over its e-mail system are not over. CREW and another private group, the National Security Archive, have sued the Executive Office of the president over the possibly lost e-mail, claiming that the EOP has failed to comply with legal obligations by failing to take steps to ensure preservation of electronic records.

In that case, a judge is considering whether to instruct the EOP on steps it must to take to safeguard electronic messages. The White House is seeking to have that suit thrown out.

The White House has acknowledged problems with its e-mail system, while saying that if any e-mail is missing, it can be found on disaster recovery backup tapes.