Tesco chief executive Philip Clarke.

London - Tesco chief executive Philip Clarke only expects to do the job for “a few years” although he does not feel any personal pressure from investors despite the market share of Britain's biggest retailer falling to a decade low.

Tesco, the world's third-largest retailer, is being squeezed between the hard discounters Aldi and Lidl and upmarket grocers Waitrose and Marks & Spencer in its home market.

Its market share fell to 28.7 percent - its lowest since 2004 - from 29.6 percent, in the 12 weeks to March 2 compared with the same period the year before, data from market researcher Kantar Worldpanel showed on Tuesday.

Asked whether he was feeling pressure from investors over Tesco's falling market share, Clarke said: “I don't feel it at all. What I feel is a much greater responsibility to the company and the stakeholders.”

“It's not a question about discounters or something else, its about doing the right thing for our customers.”

Speaking at the annual Retail Week Live conference Clarke, who took over as chief executive in 2011 after a long career at Tesco, said he did not expect to be in the job as long as his predecessor Terry Leahy who led the company for 13 years.

“You only have a job like this for a few years,” he said.

“I am not a young man, I'm 54 years of age and I've given it 40 years.”

Tesco is 22 months into a turnaround programme under Clarke, but sales are still falling at its 3,150 British stores despite spending on refits, more staff and new product ranges.

Clarke declined to comment on a Sky News report that Chief Finance Officer Laurie McIlwee, who has been with Tesco since 2009, was likely to leave in the next few months amid tensions with the chief executive. - Reuters