Retail giant Woolworths will shed an extra 400 jobs as it looks to save $500 million in costs.

Woolworths chief executive Grant O’Brien told investors on Wednesday that the company has already axed about 400 full-time positions from its back office operations.

Now a further 400 positions will be cut as the retailer accelerates its `Lean Retail’ model designed to save $500 million in costs during the 2015/16 financial year.

“We will reduce further non-customer facing roles by a further 400 positions by the end of the first half of FY16 as we continue to identify process improvements,” Mr O’Brien said on Wednesday.