Sainsbury's has had trouble getting the formula right

Maggie Miller, head of information technology at the supermarket giant will be replaced by Angela Morrison, an IT savvy director at Asda.

Ms Miller is the latest in a number of bosses who have left since the arrival of new chief executive Justin King.

The supermarket recently announced that it had ironed out its IT gremlins.

Now, Sainsbury's says it has increased the reliability of its network and distribution systems by 90% in time for the all-important Christmas trading season.

Fighting back

Once an industry leader, Sainsbury has lost out in recent years as rivals slashed prices.

UK SUPERMARKET MARKET SHARE Tesco 28.3% Asda 16.7% Sainsbury's 15.5% Morrisons & Safeway 13.2% Somerfield 5.7% Co-ops 5.1% Waitrose 3.6% Iceland 2% Budgens 0.4% SOURCE: TNS

The botching of a �3bn investment in supply-chain and IT improvements was overseen by former chief executive Sir Peter Davis.

Sainsbury's issued three profit warnings this year as problems mounted, and since the start of 2004 its shares have underperformed rival food retailers by 23%.

Under the catch line 'Making Sainsbury's Great Again', new chief executive Justin King is planning to revive the ailing retailer by getting back to basics and focusing on selling food.

But this has yet to impact on profits and last month the struggling supermarket announced its first ever loss.

For the six months to 9 October, it reported a pre-tax, post-exceptional loss of �39m ($72m), compared to a profit of �323m a year earlier.

Sainsbury's chief executive Justin King was forced to admit that the firm had been failing to properly stock its shelves because of faulty distribution systems caused by the so-called IT upgrade.

A reorganisation of the business under Mr King has already cost it �400m.