Woolworths has revealed tough conditions on the high street have continued to take their toll on the business.

But chief executive Trevor Bish-Jones said the business had "made hay while the sun shines" in more profitable areas such as outdoor furniture during the recent heatwave.

However, footfall was down for few days after the July 7 terror attacks in London.

The company revealed yesterday that same-store sales at its core chain were 4.4 per cent lower in the 24 weeks to July 16 - unchanged on an earlier update covering the first 18 weeks of the period.

In a statement ahead of half-year results, it said the retail climate had remained "difficult" and that it was continuing to take action to improve the business by keeping stock and costs under control.

The group said profit margins were still slightly below last year but added it was starting to see the impact of action taken to reverse this trend.

Woolies has enjoyed a revival under Mr Bish-Jones, lifting 2004 profits by five per cent to £73.1 million, although this has since been offset by the disappointing sales performance so far this year.

It recently said much of the drop in sales was down to a comparatively weaker release schedule in entertainment, which covers music, video, games and books.

It said in an update last month that it would respond to the downturn by shifting the focus at its 800 stores to higher profit areas, such as homeware, toys and clothing.

Mr Bish-Jones said: "The retail environment remains challenging and against this background we continue to be disciplined about controlling costs and stock while taking action to improve the group's businesses."

The group said a store refurbishment programme was on track to convert 50 stores - up to six of them in the West Midlands - to a new format this year.

Mr Bish-Jones said margins began to improve at the end of the retailer's first half, as good weather boosted sales of more profitable items such as outdoor furniture and summer fashions.

"We were able to make hay while the sun shines," he said.

"The margin performance improved due to a shift in mix - the last six weeks was characterised by hot weather so we've had good sales on high summer fashion clothing, outdoor toys, garden products and furnishings."

Mr Bish-Jones said the bombings in London on July 7 affected sales for a couple of days, as people stayed away from the high street.

"Footfall was down, but it only lasted a few days."

Woolies also said it was continuing to make progress with the sale of its entertainment chain MVC.

Analyst John Stevenson at Shore Capital said the potential sale of MVC and cash gains from the disposal of the group's big W out-of-town stores may offer some support.

However, he added: "We are somewhat sceptical of the group's prospects to deliver in tougher conditions, particularly given the increasing penetration of the superstores and discounters, notably Tesco, Primark and Asda."

The group is due to announce interim results for the 26 weeks to July 30 on September 21.