Wal-Mart Stores is planning to lay off hundreds of headquarter staff as part of the discount retail giant’s efforts to cut costs, the Wall Street Journal noted. Fewer than 500 employees are expected to lose their jobs and an announcement could be made as early as Friday, according to an un-named source. So far Wal-Mart has declined to comment. The cuts come as the world’s largest retailer struggles to shore up its profit margins, which have been weighed down by a 1 billion dollar investment announced earlier this year to increase wages for half a million store-level workers and other cost pressures. Top executives are due to present their strategy for the company at an annual meeting with analysts and investors later this month.