The grisly conditions facing UK retailers were underlined today when DSG, which operates Currys and PC World, revealed a big drop in sales of TVs and computers.

The struggling group, which has been battered by rivals on the high street and online, is cutting £30m off its investment plans.

Like-for-like sales of computers and computer equipment through its PC World outlets in the UK and Ireland were down 11% over the past 24 weeks as consumers reined back their spending.

At Currys and Currys.digital – formerly known as Dixons – the sales fall was 7%.

In the group's European operations, sales in the previously better performing Nordic countries were down 6% and there has been a 10% dip in southern Europe, which includes DSG's disastrous UniEuro chain. The group is looking for offers for its businesses in Italy and Spain.

"Consumer confidence has significantly deteriorated across Europe", said DSG.

The chief executive, John Browett, who was hired to turn around the business a year ago, said sales of laptops had slowed and flatscreen televisions – which have been powering sales – are "negative in value terms". Profit margins have also deteriorated.

Earlier this year, the former Tesco executive unveiled a "renewal and transformation plan" designed to revive the fortunes of the group, which is Europe's biggest electricals retailer.

The plan focuses on heavy investment in the stores to bring them up to date, staff training to offer better service and a complete overhaul of the products on the shelves.

Browett said today he was "being prudent" and "taking decisive action", cutting capital expenditure and lowering the stock intake, mirroring the actions being taken by many other retailers as they brace for the impact of higher unemployment.

The DSG update came as official data showed sales growth has slowed sharply.

Several other retailers have also reported increasingly tough conditions this week. Debenhams said recent sales were down 4% and Home Retail Group, which owns the Argos catalogue shops chain and the Homebase DIY stores, said trade was tougher than at any time since Argos was founded 35 years ago and recent sales were down 9% on last year.

Today, Sports Direct said it was "battling the toughest trading conditions it has ever faced" in its 25-year history. Its shares, which floated in February 2007 at 300p, were changing hands at only 36.5p today.

Browett said fears of a complete retail meltown could be wide of the mark: "I've operated in a lot of recessionary environments. I've seen very bad markets before. But this is not the end of the world. I'm a bit surprised by the Armageddon-type headlines... it doesn't feel like a global slump of epic proportions. There are still people out there willing to shop."

He is pressing ahead with plans to refurbish the group's stores and has completed makeovers on 40 PC World stores, seven Currys' superstores and four Currys.digital outlets.

Last week, the group opened its first 55,000 sq ft megastore, at J9 of the M6. There was traffic chaos on the motorway as shoppers arrived in droves to buy specially-discounted goods.

Browett refused to say how the new-look stores were performing, saying only "so far, so good". There has been speculation the refurbished stores are seeing sales uplifts of about 20%.

Browett said it was "still full steam ahead" for his renewal plan, although DSG has pared back the cost of the revamps and he would only reconsider the updates if there was a "major" economic collapse.

He played down the threat posed by US giant Best Buy, the world's biggest electricals retailer, which has linked with Carphone Warehouse to open 100 vast stores across Europe by 2013.

The impact Best Buy might have, he said, was being exaggerated, as it will have only three or four stores in the UK by the second half of next year. "It really isn't a big factor in our business", he said.

DSG shares, which have lost 80% since Browett joined the business, were up 1.75p at 25.25p, a rise of nearly 8%.

Analyst Freddie George at Seymour Pierce still rates the shares a sell. "Although the stock has been a significant underperformer, we continue to believe there is too much overlap between PC World and Currys; the Nordic markets are becoming more competitive, putting margins under pressure, and there is likely to be disappointment that there has not been more progress with selling UniEuro, Italy, or the Spanish operation," George said.