Shares in struggling online voucher firm Groupon have plummeted more than 27% to a new low after it reported worse-than-expected results on Thursday.

Wall Street investors dumped the stock after the company, which was once the world's fastest growing online firm, said sales had slowed of its daily discount voucher offers for everything from yoga classes to plastic surgery.

Having traded at $20 a share when first floated less than a year ago, the shares were languishing at $2.85, down 27% on the day.

Sales in the three months to the end of September were up 32% on the same period last year to $568m (£355m). But revenues were flat compared with the previous three months. Losses were $3m compared with $54.2m last year.

The bulk of the revenues came from the Groupon Goods retail arm that sells items such as sunglasses, toys, and big-screen televisions. It generated $145m in revenues but Groupon spent $127m on inventory, shipping and marketing.

It is the latest in a long line of disappointments from the company, with investors seemingly showing their dissatisfaction with the business.

In April the company issued a profit warning after admitting it should have added an extra $22m loss into its accounts due to the high level of disgruntled customers demanding refunds.

It is also facing an investigation by the US Securities and Exchange Commission into its accounting and its controversial decision to restate its accounts shortly after listing. In the UK an Office of Fair Trading investigation found Groupon guilty of widespread breaches of consumer protection laws, relating to issues including the pricing, advertising and unfair terms attached to its daily deals.