WASHINGTON (Reuters) - Lockheed Martin Corp will announce plans on Wednesday to lay off about 500 people across its information systems and government services division, which it plans to sell or spin off later this year, a person familiar with the plans said.

The job cuts would be both voluntary and involuntary, and should be completed by mid-November, said the person, who was not authorized to speak publicly on the matter and so declined to be identified.

Lockheed in July announced it would buy Sikorsky Aircraft, a unit of United Technologies Corp for $9 billion, and said it would carry out a strategic review of alternatives for its information technology and government services division.