House and Senate negotiators are likely to file a final FY ’12 defense appropriations bill by day’s end that provides the Pentagon a $5 billion boost in funding over last year and continues a disputed vehicle program.

The two chambers’ appropriations committees worked late last week on an omnibus spending bill for most federal agencies, and the defense portion was nearly complete late Friday. House and Senate lawmakers agreed to grant a $518 billion base defense budget, which is $5 billion more than in FY ’11, according to sources.

The decision is a victory for military-spending advocates. The Senate Appropriations Committee (SAC) in September called for level funding the Pentagon at $513 billion in FY ’12, granting $26 billion less than the $539 billion the White House initially requested back in February. The SAC’s funding, supported by the White House, was intended to jibe with the Budget Control Act President Barack Obama signed in August. The House had approved a defense appropriations bill in July with a smaller $9 billion cut to the initial $539 billion Pentagon plan.

One program that will benefit in the $518 billion defense bill is the Joint Light Tactical Vehicle (JLTV), the Humvee-replacement program that is funded over the Senate’s previous objection, sources said.

Three teams have built JLTV prototypes: General Dynamics [GD]-AM General; BAE Systems-Navistar Defense LLC, an affiliate of Navistar International Corp. [NAV]; and Lockheed Martin [LMT]-BAE.

The SAC in September proposed killing the program, now in the Technology Development (TD) phase, for which the Army sought $172 million and the Marine Corps requested $71.8 million. The defense bill the House passed in July proposed preserving JLTV but trimming the overall funding request for it by $50 million.

The SAC cited multiple JLTV concerns, including requirements changes, an extension of the scheduled Engineering and Manufacturing Development (EMD) phase, and a doubling of projected EMD costs. However, Army and Marine Corps officials fought on Capitol Hill to save the vehicle, touting new requirements and cost-savings they agreed to in recent months.

The defense appropriations bill is slated to be filed as part of an omnibus package funding most of the government for FY ’12, which began Oct. 1. Lawmakers and aides talked late last week about filing the massive bill tonight, lining up a House vote Thursday and Senate action no later than Friday, when a short-term government funding bill will expire. That so-called continuing resolution has kept the Pentagon’s FY ’12 funding at 1.4 percent below FY ’11 levels and prevents it from entering into new contracts.

Meanwhile, the policy-setting FY ’12 defense authorization bill was still unfinished last Friday. Senate Armed Services Committee leaders continued to wrestle with the Obama administration’s objections to military-detainee language in the Senate version. House and Senate lawmakers met last week to reconcile their differing versions of the bill, and lawmakers said Thursday most of the differences had been settled.

With Congress working on defense legislation for the current fiscal year, Chairman of the Joint Chiefs of Staff Army Gen. Martin Dempsey talked last Friday at a Washington think tank event about future budgets during austere times.

The Pentagon is still working on the five-year budget for 2013 to 2017 that it will send to Congress next February, he said.

“It doesn’t lock until we’re on or about the 6th of February,” he said at the Atlantic Council forum. “So that’s why (Defense) Secretary (Leon) Panetta has been very careful to make sure we all know nothing is decided until everything is decided.”

The Budget Control Act reduced the Pentagon’s decade-long spending plans by more than $450 billion. Those cuts will translate into a $260 billion reduction to the five-year defense budget proposal, Panetta has said.

Changes in the five-year plan will be “significant” Dempsey said last Friday.

He insisted the Pentagon has not examined how it would be impacted by additional cuts of up to $600 billion that it could receive because Congress’ Joint Select Committee on Deficit Reduction failed to come up with a plan to cut additional federal spending. The budget-control law signed in August says if the panel failed the Pentagon would receive the added reductions through a sequestration process, bringing its decade-long cuts to roughly $1 trillion.

“I will say this, and I say (it) with great integrity: We have not done any thinking or any work on what further cuts might come,” Dempsey said. He said he instead has focused on preparing the Pentagon and its budget for where they need to be in 2020.