Lockheed Martin Corp , the world's biggest defense contractor, said on Tuesday it is offering early exit incentive packages to its directors and vice presidents to cut costs as growth in U.S. defense spending slows.

The incentives apply to executives willing to leave the company by February 1, 2011, under the voluntary program.

The move is intended to cut overhead costs and management layers as well as give other workers opportunities to take on broader assignments, the company said.

We're taking bold and responsible action to address the new reality of our business environment consistent with our customers' need to improve efficiency and deliver additional savings, Lockheed Martin Chairman and CEO Bob Stevens said in a statement.

Our customers are facing increasing demands with constrained resources, and they're relying on us to give them the very best value within these constraints, he added.

Lockheed, based in Bethesda, Maryland, has about 136,000 employees.

(Reporting by Karen Jacobs; Editing by Richard Chang)