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

The 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 Administrative “are strictly administrative,” Ms. Kollar-Kotelly ruled.

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.

The administration says the Office of Administration has no substantial authority independent of President Bush and therefore is not subject to the disclosure requirements.

Despite Ms. Kollar-Kotelly’s decision, 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, claiming that the EOP has failed to comply with legal obligations by failing to take steps to ensure preservation of electronic records.

A judge is considering whether to instruct the White House on steps it must to take to safeguard electronic messages. The White Houes is seeking to have that suit thrown out.