Shares in appliances retailer AO World fell by almost half after it warned its full-year profits would be lower than expected.

The Bolton-based online business now believes its UK full-year earnings will be around £16.5 million, blaming Black Friday sales which did not produce additional revenues but instead condensed them into a shorter period.

Brokers at Jefferies had expected the firm's UK business to make £19.2 million after the firm's founder and chief executive John Roberts said last month he was confident of meeting full-year targets. Shares fell as much as 47% today.

The company, which was launched in 2000, floated on the stock market last year and launched in Germany in October, six months ahead of expectations.

It added its UK annual sales would come in at between and £470 million and £475 million. Brokers at JPMorgan had forecast £486 million.

Chief executive John Roberts said: "AO has experienced tougher than expected trading conditions in the final quarter of the year, as compared to the fourth quarter in the 2014 financial year.

"While we are disappointed that sales and profits are going to come in slightly below expectations, we remain committed to our market-leading, customer-focused business model."

The firm added that trading in Germany is progressing well and it is looking at other areas for international expansion.

Analysts at JPMorgan said: "Given the relatively low level of profitability currently being achieved by the group, this represents a material downgrade to estimates."

In May it introduced the sale of audio visual goods such as TVs, to sell alongside its more usual larger items such as washing machines and fridges.

Since AO World floated on the London stock market last February, at 285p a share, it has consistently traded below its offer price.