SUPERMARKET Tesco has said it will close 43 unprofitable stores across the UK - a "significant proportion" of which will be local convenience shops.

The firm is also shelving plans to open a further 49 new "very large" stores.

Additionally, Tesco is closing its staff pension scheme, will make cuts of £250m, and reduce overheads by 30 per cent.

It comes after two years of troubles at Tesco, which has suffered falling sales and profit warnings.

Last year, the company was embroiled in an accounting scandal, and saw the departure of some senior executives.

It extends a miserable run for Tesco. Here is a timeline of the supermarket's performance since Philip Clarke took the helm in 2011.

:: February 2011

Sir Terry Leahy steps down as chief executive on his 55th birthday after 14 years in charge, overseeing a leap in pre-tax profits from £750m in 1997 to £3.4bn at the group's last set of annual figures in April 2010. The market share of the group stands at 30.5 per cent.

:: January 2012

Less than a year into Mr Clarke's tenure, Tesco shocks the market with its first profit warning in almost 20 years after poor Christmas trading. Shares plunge by as much as 15 per cent, or more than £4bn, as it finds itself squeezed by discounters Aldi and Lidl and upmarket Waitrose and Marks & Spencer.

:: April 2012

Tesco unveils a £1bn UK revival plan, which includes upgrading stores, the recruitment of more staff and better prices and value. The initiative follows complaints that its 2,800 stores are cold and industrial with poor levels of service.

:: April 2013

The retailer reports its first fall in annual profits in 19 years, with post-tax profit tumbling almost 96 per cent to £120m from a year earlier. The figure is hit by a £1.2bn charge on the retailer's US Fresh & Easy chain of around 200 stores as it confirms it will leave the country. The firm also suffers a £804m write-down in the UK on land for more than 100 major stores, bought at the height of the property boom, which will no longer be developed.

:: February 2014

The supermarket promises to spend an additional £200m on lower prices for basic products, such as carrots, tomatoes, onions, peppers and cucumbers. It will also rein in annual capital spending to no more than £2.5bn for at least the next three years as a result of the dramatic reduction in store expansion - nearly half the £4.7bn spent in 2008/09.

:: April 2014

Mr Clarke brushes off speculation about his future despite little sign that his £1bn plan to turn around the retail juggernaut is bearing fruit. Profits fall 6.9 per cent to £3.05bn for the year to February 22 while fourth-quarter like-for-like sales slump by 3 per cent as its UK market share falls to 28.6 per cent in the 12 weeks to March 31, from 29.7 per cent in the same period a year earlier.

:: June 2014

Till-roll figures from Kantar Worldpanel show a decline in Tesco's market share to 29 per cent in the 12 weeks to May 25, compared with 30.5 per cent a year earlier. A day later, the chain reports a 3.7 per cent fall in like-for-like sales for the first quarter of its financial year. It is a performance that Mr Clarke admits is the worst he has seen in four decades at the supermarket chain.

:: July 2014

Tesco announces that Mr Clarke will step down from the board on October 1 to be replaced by Unilever executive Dave Lewis. Sales and trading profit in the first half of the year are "somewhat below" expectations, the company adds.

:: August 2014

The change at the top of the supermarket is brought forward by a month in order to allow Mr Lewis to commence a review of ''every aspect'' of the group's operations. The move comes after the chain reveals another profits warning and slashes its dividend to shareholders by 75 per cent.

:: September 2014

The previous month's guidance turns out to be too optimistic as the company reveals it has overstated profits by £250m. It asks Deloitte to carry out an investigation into the error, which relates to timing issues on when Tesco's UK business reports the income it receives from suppliers.

:: October 2014

The Financial Conduct Authority launches a probe into the dodgy numbers as the company suspends a total of eight executives. US investment guru Warren Buffett off-loads his Tesco shares, labelling his investment a "huge mistake". When its latest figures are finally published they reveal a 91.9 per cent plunge in first half pre-tax profits to £112m. Tesco also reveals the original overstatement estimate was an understatement - £263m, not £250m. The group's chairman Sir Richard Broadbent says he is preparing to step down saying "the issues that have come to light are a matter of profound regret". Days later Tesco is formally placed under criminal investigation by the Serious Fraud Office.

:: December 2014

Dave Lewis spells out the scale of the problems facing Britain's biggest supermarket as it issues a £500m profits warning. The accounting watchdog the Financial Reporting Council (FRC) then launches an investigation into the £263m profits overstatement.

:: January 2015

Tesco announces it is shutting its head office as well as 43 unprofitable stores as part of a raft of new measures as new boss Dave Lewis battles to turn around the group's fortunes.