Morrisons also joined rivals in signalling an end to rapid expansion of new space. It will slash its space growth to around half the rate over the past five years, at 350,000 square feet annually.
In future it expects sales growth mainly to be driven by online and convenience, both of which use less capital than opening big new stores.
Turnover was level at £8.9 billion, but net debt surged to £2.5 billion from £1.7 billion a year earlier as it invested heavily.
Analysts had on average been expecting like-for-like sales to decline 1.5% over the half. They expected pre-tax profits to slide 13% to £383 million from £440 million a year earlier.