An e-business consultancy singled out by the CBI last year as Britain's most promising young business yesterday laid off a quarter of its staff.

Rubus, which advises firms on how to make the most of commercial opportunities presented by technologies such as mobile phones and interactive television, said 70 staff would be cut from its 300 workers owing to "rapidly changing market conditions".

"It is a painful decision to make but we have anticipated the changing direction of the market and this is a prudent measure to put the company in good shape for the future," founder and chief executive Michael Walton said.

Mr Walton explained that the declining fortunes of business-to-consumer internet firms meant Rubus was getting less work from dot.coms and would focus more on helping large corporations adapt to the opportunities of new technology. It would increasingly compete with big consultancy firms such as IBM and PricewaterhouseCoopers.

Rubus clients include Waterstones and Thomas Cook, television firms Granada Media and ONdigital and investment banks Nomura and Cazenove.

Mr Walton emphasised that Rubus's two main investors, private equity firms Schroder Ventures and Warburg Pincus, were committed to the business's long-term future and that it had enough cash to see it through to profitability.

Rubus this year considered floating on the stock market but volatile conditions that also affected US e-business consultancies had put paid to the plans for now, Mr Walton said.