FACTBOX: Senate passes $636 billion defense spending bill

WASHINGTON (Reuters) - The U.S. Senate on Tuesday approved $636 billion to fund military operations for the fiscal year that started on October 1, $3.9 billion less than requested by the Obama administration.

Lawmakers must resolve differences with a similar spending bill passed by the House of Representatives before President Barack Obama can sign it into law.

Following are some key provisions of the bill, which passed by a vote of 93 to 7:

* $128.2 billion would fund the wars in Iraq and Afghanistan. Congress in prior years funded the two wars separately from regular Pentagon operations.

* The bill would end production of Lockheed-Martin Corp.'s F-22 fighter plane and the VH-71 presidential helicopter, also made by Lockheed. The Pentagon has said it does not need these aircraft.

* The bill likewise contains no funding for an alternate engine for the F-35 Joint Strike Fighter, which is being built by General Electric Co and Britain's Rolls-Royce Group Plc.

However, the engine program could survive despite a White House veto threat. The House has approved $560 million for the program and lawmakers from both chambers have agreed to include that money in a separate bill that sets the Pentagon's budget.

* The bill allocates $2.5 billion to continue production of Boeing Co.'s C-17 cargo plane -- another program the Pentagon had sought to shut down.

* It prohibits the Obama administration from transferring international terrorism suspects currently held at the Guantanamo Bay military prison to the United States.

* It includes $2.7 billion for hundreds of lawmakers' pet projects, from a World War Two museum to a civic-education center named for the late Senator Edward Kennedy, that the Pentagon did not request. Such "earmarks" serve as a lightning rod for budget hawks concerned about runaway federal spending, but senators turned back several attempts to strip them out.

* $7.7 billion for missile defense, a $1.4 billion cut from last year.

* $154 billion for operations and maintenance, which is $2.4 billion less than the Pentagon wants.

* $125 billion to pay salaries and other personnel costs for 1.43 million active-duty troops, including an increase of 22,000 troops for the Army, and a reserve force of 845,000.

* The bill provides $3.65 billion to build two DDG-51 destroyers, one more than the Pentagon wants.

(Reporting by Andy Sullivan; Editing by Cynthia Osterman)