BETHESDA, Md. — Lockheed Martin said Thursday that it is cutting 4,000 jobs, about 3.5 percent of its workforce, as the defense contractor looks to lower costs amid reduced government spending.The cuts will not affect the company’s two North Texas operations: Lockheed Martin Aeronautics in west Fort Worth, where more than 14,000 people work, and the Missiles and Fire Control division in Grand Prairie, which has 2,700 employees.“In the face of government budget cuts and an increasingly complex global security landscape, these actions are necessary for the future of our business,” CEO Marillyn Hewson said in a statement Thursday. Across-the-board spending reductions by the government have helped trim U.S. deficits. Budget negotiators in Congress are holding talks to find ways to cut spending and tax breaks to replace the automatic cuts, known as sequestration, that started this year and are slamming the Pentagon and domestic agencies.Lockheed Martin, which is based in Bethesda, Md., and makes the Patriot missile defense system and the F-35 and F-16, will close an information systems facility in Goodyear, Ariz.; a mission systems and training site in Akron, Ohio; a space systems plant in Newtown, Pa.; and a missile facility in Horizon City, near El Paso. The company will also close four buildings at its Sunnyvale, Calif., campus by mid-2015, eliminating 2,000 jobs.Another 2,000 positions will be cut in its information systems and global solutions, mission system and training, and space systems units by the end of next year.The Horizon City facility handled production of the Army Tactical Missile System, which has seen declining production in recent years. That closure will affect only 11 employees, with work shifted to a plant in Camden, Ark.Lockheed said it will shift other work and employees to facilities in Denver and Valley Forge, Pa. The company is also reviewing other possible plants to which it could relocate programs, including facilities in Owego, N.Y., and Orlando, Fla. Lockheed Martin said it has cut its workforce to 116,000 from 146,000 since 2008. Last month, it said revenue will decline “slightly” next year on likely federal budget cuts. Pentagon officials have protected major weapons systems from deep cuts, including by locking in contracts for the F-35 program before the automatic reductions took effect in March.They have said weapons procurement won’t be spared in coming years unless President Barack Obama and Congress agree on a plan to call off sequestration.“You can’t hold the F-35 harmless” if the Pentagon must continue to live under declining budgets, said Robert Levinson, an analyst with Bloomberg Government. “The cuts in other programs would be way too dramatic.” This report includes material from The Associated Press and Bloomberg News.