Tesco has announced it will close 43 stores as well as its Cheshunt headquarters, and sell assets including its Blinkbox streaming service and Dunnhumby data business.
Britain's biggest supermarket will also review new shop openings and is closing its final salary pension scheme. Tesco said it will move from its Hertfordshire head office in 2016 to new premises in Welwyn Garden City.
The restructuring of its business is expected to shore up up £250m.
Tesco chief executive Dave Lewis said: "We have some very difficult changes to make. I am very conscious that the consequences of these changes are significant for all stakeholders in our business but we are facing the reality of the situation.
"Our recent performance gives us confidence that when we pull together and put the customer first we can deliver the right results."
Tesco reported overall like-for-like sales were down by 2.9% for the three months to the beginning of January. The group has reported a 5.4% decline in the previous quarter.
Tesco reported sales drop of 0.3% on last year's festive period, which was a better than expected result, and with fuel added, sales for the period were up 0.1%.
The closures and asset sales will lead to inevitable job loses and come after a disastrous year for the retailer, which has seen 43% wiped off its share price.
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