Asda’s operating profit rose almost five per cent to £998.6m last year, excluding charges such as royalties to parent Walmart.

Including such expenses, operating profits fell 10.4% to £803.5m.

Panmure analyst Philip Dorgan, who has studied the Walmart-owned grocer’s latest Companies House filing, said that like-for-like growth in 2010 was 0.6% and that total sales were ahead 3.6% to £20.5bn.

Dorgan calculated that Asda’s operating margin advanced by 10 basis points to 4.9%.

He said: “Asda’s Companies House filing for 2010 shows that it had an average year, albeit marginally beating Tesco’s UK sales and profit performance.

“Of course, Asda’s numbers have many adjustments to them, being a subsidiary of Walmart, so perhaps we shouldn’t read too much into this, or the fact that its operating margin remains well below Tesco’s.”

He observed: “It is interesting to note that Asda paid £778m for Netto, which compares with its book value of £321m, although at the year-end it had not worked out what the fair value of the acquired business was, so this latter number could be written up. “