Sales at Asda continued to rise in the fourth quarter, as the supermarket awaits the next stage in its proposed merger with Sainsbury’s.

Like-for-like sales were up 1%, marking the seventh consecutive quarter of growth.

Meanwhile net sales rose by 2.7%.

Asda boss Roger Burnley said it had been another “challenging” period in retail, but fourth-quarter sales were driven by higher demand for the grocer’s own-brand products, especially the premium Extra Special range.

“The year ahead looks no less turbulent than the last, with uncertainties around Brexit playing on our customers’ minds,” he said.

“Whilst I am pleased with our performance in 2018, we must remain focused on ensuring the long-term sustainable success of Asda for our customers.”

Growth in the fourth quarter slowed compared with the previous period, when the summer heatwave and World Cup helped to boost comparable sales by 2%.

Thomas Brereton, retail analyst at GlobalData, called the latest numbers “lacklustre” and said they may come as a surprise for Asda.

“After dropping its price guarantee scheme in September to increase focus on ‘everyday low prices’, it poured investment into staying price competitive with the discounters, and also sparked a fuel price war in November,” he said.

“With ever-savvy consumers continuously looking to save money on their food shopping, it seems a natural move for Asda to make; unfortunately, it has not directly translated into a victory for the EDLP (everyday low price) grocer – at least not to the extent it would have liked.”

The results come as Asda and Sainsbury’s await the provisional findings of a competition inquiry into their proposed mega-merger, which are expected this month.

The Competition and Markets Authority (CMA) will publish the provisional decision ahead of a statutory deadline, which has been extended to the end of April.

It is expected to include proposed remedies for the merger, including the possible disposal of stores.

The watchdog this month extended the deadline for its final decision by almost two months, citing the scope and complexity of the deal.

If the move goes ahead, 42% of the combined business will be held by Asda’s current owner, Walmart.

The US retail giant reported a quarterly increase of 1.9% in global revenue on Tuesday.

For the full year, revenue climbed 2.8% to 514.4 billion dollars (£398.19 billion).

Walmart president and CEO Doug McMillon commented on the company’s UK business, saying it would keep prices low despite Brexit uncertainty.

“In the UK, Brexit – and the potential implications of a hard Brexit – is increasingly on the mind of everyone,” he said.

“No matter the situation, Asda will always work to keep prices as low as possible for its customers. I visited our team in the UK a few weeks ago, and am really impressed with their performance, attitudes and leadership. They’re amazing.”