The national intelligence director has won White House approval to begin revising an executive order that lays out each spy agency's responsibilities and the government's protections against spying on Americans.

The Reagan-era 1981 presidential order is woven into the culture at the 16 spy agencies and spells out their powers. It also provides fundamental guidance to protect against spying on Americans, prohibitions against human experimentation and the long-standing ban on assassination.

Some officials familiar with Intelligence Director Mike McConnell's plans, speaking only on condition of anonymity because the deliberations remain internal, said his intent is solely to update the policy to reflect changes in the intelligence community since Sept. 11, 2001, including the creation of his own office.

But other officials, who also spoke on condition they not be identified, said opening the order to changes could lead well beyond that. They said the exercise could threaten civil liberties protections approved by President Reagan following intelligence abuses in the 1970s, and that intelligence agencies will be tempted to expand their powers.

McConnell himself has said the authorities of his office need to be adjusted. "We don't have it right yet," he told an audience in April.

In a recent interview, Vice Adm. Robert Murrett, director of the National Geospatial-Intelligence Agency, characterized the effort as an "overhaul" aimed at helping all 16 spy agencies work more closely together. He said the discussions about the order — known by its number, 12333 — are still in the early stages.

Murrett has told McConnell he supports the effort. "I've told him I think it's time. I think his intentions in taking another look at 12333 are right," Murrett said, noting the document is a quarter-century old.

The debate comes at a politically touchy time, with President Bush still under scrutiny for his post-9/11 intelligence-gathering methods. McConnell, who became spy chief in February, is expected to be in the job until the end of the Bush administration, and some officials believe he would like to leave his mark on national security issues like this one before leaving office.

The effort to redo the executive order comes as McConnell has been pushing a skeptical Democratic Congress to overhaul a landmark law that provides the rules of the road for foreign intelligence investigations on U.S. soil, known as the Foreign Intelligence Surveillance Act. Lawmakers have demanded more information about government surveillance before they act, but the administration has thus far been unwilling to respond to all of their requests.

Unlike the surveillance law, the White House can change an executive order without congressional or judicial approval.

McConnell's spokesman, Steve Shaw, said he would not comment on internal deliberations of U.S. spy agencies but noted that the director's 100-day plan unveiled in April promised to change statutes, regulations and directives that need updating.

Kate Starr, a spokeswoman at the White House's National Security Council, said she would not comment on executive orders before the president signs them.

Reagan's executive order was signed Dec. 4, 1981, and laid a foundation for the intelligence community by providing a roadmap for each agencies' responsibilities.

"It is sort of the basic rule book for running the intelligence community," specifying who is part of it and what their roles are, said Jeffrey Richelson, a senior fellow with the National Security Archive and an expert on presidential intelligence directives. "It is certainly outdated in that ... you have elements of the intelligence community that weren't in it when this thing was written."

For instance, the order doesn't discuss the powers of the national intelligence director, created by Congress in late 2004 to oversee all U.S. spy agencies in response to the intelligence failures of 9/11 and prewar Iraq. Instead, the order directs intelligence agencies to respond to requests from the CIA director, who headed the intelligence community for decades before the creation of McConnell's office.

Among other flaws, the order doesn't reference two major defense spy agencies — the National Reconnaissance Office, which operates spy satellites, and the National Geospatial-Intelligence Agency, which analyzes imagery. Nor does it explain the FBI's domestic intelligence mission, which has gotten increasing attention since 9/11.

The order also created guidelines to prohibit spying on Americans. Senior intelligence officials say officers frequently refer to the order as they do their work around the globe.

But civil liberties advocates say the executive order isn't strong enough now because it didn't prevent the Bush administration from running controversial operations including the National Security Agency's warrantless domestic eavesdropping program.

Lisa Graves, deputy director of the Center for National Security Studies, said the administration has pointed to the executive order as evidence that Americans are protected from government spying. But the order "doesn't provide adequate protection now for civil liberties. Any watering down would be problematic," she said.