SALES at one of the North East's fastest-growing listed companies are under pressure as more rivals muscle into the niche life sciences market which had made it one of the region's biggest success stories.

Brokers yesterday dropped their full-year forecasts for the Boldon-based Immunodiagnostic Systems, despite a strong set of interim results.

There is concern that the rapid growth of the vitamin D testing firm will not be sustained at such as fast pace once rivals move into the lucrative US market.

Despite those worries, IDS reported a 21% rise in revenues to £27.3m for the six months to the end of September with a 155% increase in sales of its flagship IDS-iSYS vitamin D testing machine. The company’s profits also rose by 17% to £7.7m.

But competitor Siemens launched its vitamin D test in the US last month and Roche and Abbott are expected to follow shortly, meaning that IDS’s existing and potential customers have tended to wait before deciding which service to go for. There is also the spectre of spending cuts hanging over the US health service.

IDS chief executive Ian Cookson said: “The vitamin D market has narrowed and as a result, the trading environment for the second half has been revised.

“Our in-house brokers have reviewed their estimate for the full year revenues to £57.2m but that is still £7m more than last year. It is still good growth but not as fast we had hoped.”