WASHINGTON (Reuters) - The death of Democratic Senator Daniel Inouye marks another significant reduction in Congress' troop of defense champions, but experts say the Pentagon will still face big obstacles any time it tries to scrap arms programs or cut military bases.

Inouye, who chaired the Senate Appropriations Committee, died on Monday. Other high-profile hawks are leaving Congress in coming weeks after losing elections or announcing their plans to retire.

Among those departing are Senators Dick Lugar, an Indiana Republican, and Joe Lieberman, a Connecticut independent, as well as Representative Norm Dicks, a Democrat from Washington sometimes dubbed the "congressman from Boeing."

At first glance, the changes - coupled with mounting pressure to cut U.S. military spending - might seem to offer new life to efforts by top Pentagon officials to retire aging weapons and reduce waste.

But analysts, defense officials and industry executives say the changing of the guard is not likely to make much of a difference. They say lawmakers keen to preserve jobs and funding for their home districts will continue to resist calls for shrinking the size of military forces or scaling back installations.

For years, top Pentagon leaders have sought to retire aging C-5A transport planes and other older weapons only to face opposition from lawmakers concerned about losing jobs.

Congress has ultimately allowed military leaders to cancel a few, selected programs in recent years, but House and Senate negotiators on Tuesday unveiled a compromise fiscal 2013 defense authorization bill that added $1.7 billion to the Pentagon budget requested by President Barack Obama.

Among other things, the measure blocked the Navy's plans to retire three cruisers to lower operating expenses and rejected the Air Force's attempt to drop one model of Northrop Grumman's high-flying unmanned Global Hawk spy plane.

It also added money for Abrams tanks built by General Dynamics Corp and BAE System's Bradley fighting vehicles, and scaled back Air Force plans to retire warplanes used by National Guard and reserve units.

Those actions were no surprise, said Lexington Institute analyst Loren Thompson: "The changes made ... to the Pentagon's budget request demonstrate that the political system is geared to spending money rather than saving it."

That trend was likely to continue, said Thompson, although the expected nomination of former Senator Chuck Hagel to replace Defense Secretary Leon Panetta could offer a glimmer of hope for the Pentagon's drive to reform the way it buys arms.

"What Chuck Hagel brings to the table is a lot of political experience and an open mind that will not resist new ways of doing business," Thompson said.

Chris Hellman, with the nonprofit National Priorities Project, said Hagel's expected nomination was intriguing, but he said the loss of some defense hawks would probably not affect the status quo.

"The nature of the process works against reform," Hellman told Reuters. "I have no confidence that Inouye or the others will be replaced by people who are fiscal conservatives or Pentagon skeptics."

One senior industry executive said the lawmakers tapped for key roles on defense appropriations or authorization committees were precisely those who represented states with big military facilities or arms manufacturing plants.

The legacy of stalwarts like John Murtha, a late congressman from Pennsylvania and former House Appropriations Committee chairman who was famous for his defense earmarks, and Senator Ted Stevens of Alaska, who headed the Senate Appropriations Committee for many years, lived on, said the official. "They're elected to bring stuff home."

Congress has not killed a weapons program in recent memory, he noted, and nearly all program cancellations that have survived were initiated by the Pentagon.

Former Vice President Dick Cheney learned about congressional defiance when he was defense secretary in the early 1990s and tried unsuccessfully to cancel the V-22 tiltrotor aircraft built by Boeing Co and Textron Inc Bell Helicopter unit.

More recently, lawmakers responded to strong lobbying efforts by Boeing by repeatedly adding funding for C-17 transport planes despite the Air Force's adamant assertions that it had more than enough cargo- and troop-carrying capacity.

For years, they also funded a second engine built by General Electric for Lockheed Martin Corp's F-35 Joint Strike Fighter program, a move proponents said was aimed at maintaining competitive pressure on the main engine builder, Pratt & Whitney, a unit of United Technologies Corp.

Jim McAleese, a Virginia-based defense consultant, said the Pentagon ultimately succeeded in ending funding for the C-17 and GE engine, as well as the Marine Corps' troubled Expeditionary Fighting Vehicle program run by General Dynamics, but then lost the battle on items like Global Hawk and other programs.

Pentagon acquisition chief Frank Kendall has racked up some successes and was prepared to continue the fight, he said.

"It is clear that the department is very focused on acquisition reform ... but that hasn't stopped Congress from opposing any moves that would reduce force structure," said McAleese. "At the end of the day, all politics is local."