Tesco chief executive Dave Lewis has refused to blame past management for the company's current problems, after the retail giant announced pre-tax losses of £6.4bn (€8.9bn, $9.57bn), the biggest annual loss in its history.

Lewis, who was appointed CEO of Tesco in August 2014 after working at Unilever, admitted in an interview with ITN that the company had endured a tough year but refused to point the finger at previous heads Terry Leahy and Philip Clarke for the current problems.

"It's not for me to talk about the history and I don't see any benefit in doing that," Lewis said. "As a business person, having 30 years' experience of running a business, I've learnt you don't make an assessment of somebody else's situation that you weren't in. It's simple to do, but it's inapporpriate and I won't do it.

"Rather than try and understand how we got here, my whole attention is improving the offer going forward."

Tesco reported an increase in like-for-like sales in the UK, which were up by 1% in quarter four – the first time they have risen in four years. Shares in Tesco rose by more than 2% to 240.04 in early morning trading following a rise in sales.

Tesco's financial situation became suddenly chronic in 2014 after it was found to have overstated earnings by £263m.