One in seven shops on the UK's high streets stood empty in 2011 and further closures are expected this year as more people shop online and in out-of-town centres.

Town centre vacancy rates stabilised last year at an average of 14.3%, or 48,000 shops, according to a report by the Local Data Company, despite a spate of high-profile retail administrations including Barratts, Jane Norman and The Officers Club.

But while some high streets are still thriving, particularly in the south of England, the report warned many centres are "locked in a spiral of decline".

With 2012 expected to see a further fall in consumer confidence, rising unemployment, the continued growth of supermarkets and the internet and uncertainty in bank lending, it predicts the vacancy rate will rise again.

It said the high street faces "structural issues", with the internet's share of the shopping market having doubled in the past 11 years and out-of-town centres also seeing growth, meaning that "there will be, if not already, too many shops on the high street".

Prime town centre locations have generally remained healthy but secondary centres in outlying areas have been the biggest losers as they struggle to compete with town retail parks and the internet

The report also confirmed a north-south divide in the health of high streets, with most of the locations with above average vacancy rates in the Midlands or the North.

Stockport was the worst centre with a vacancy rate over 30%, while Nottingham, Grimsby, Stockton-on-Tees, Wolverhampton, Blackburn, Walsall and Blackpool all had more than a quarter of shops empty.

Although York and Harrogate had vacancy rates below 10%, the best performing centres were mainly in the south and west. These included Exeter, Kingston, Camden, Cambridge, Taunton, Salisbury and St Albans, which was the best performer with an 8.2% vacancy rate.

The survey revealed that the squeeze in consumer spending was also hurting shopping malls, with one in five suffering financial difficulties.

LDC director Matthew Hopkinson said: "The stable top line rate of 2011 hides the significant breadth in town centre vacancy rates up and down the country and the structural issues that are at stake.

"The reality is that the odds are stacked against a positive take-up of shops and as such the new reality of 48,000 empty shops is here to stay unless an alternative use or purpose can be found."

Liz Peace, chief executive of the British Property Federation, said: "Today's figures show that while some high streets are thriving, others remain locked in a spiral of decline."

She added that it was vital for measures to save the high street, including those suggested by retail guru Mary Portas, to be brought in as soon as possible. Ms Portas's suggestions include national market days and more free parking.

British Retail Consortium director general Stephen Robertson said: "It's a small mercy that shop vacancy rates are not rising but they are still worryingly high in many locations.

"The government should be keeping down the cost pressures it is responsible for. Most urgently, it should reduce the eye-watering 5.6% business rates increase it plans to impose in April."

Local Government Minister Grant Shapps said: "It is clear that while some high streets are thriving, others face stiff competition from internet shopping and out-of-town shopping centres. That's why we already have responded rapidly to recommendations in Mary Portas's review on the future of high streets and will publish our full response in the spring.

"A new competition will give 12 town centres across the country the opportunity to become 'Portas Pilots', so they can benefit from government funding and expert support to breathe new life into their town centre. And later in the year markets across the country will hold a fortnight of special events, where they will lend their expertise to budding entrepreneurs who want to try their hand at running a business.

"The government has also scrapped Whitehall rules that instructed councils to hike parking charges, given councils new powers to cut business rates for local firms, and doubled small business rate relief, which will help half a million small firms for the next two-and-a-half years."