CASCADE Technologies has been sold to a US engineering giant in a deal believed to value the company at around £40m putting managing director Iain Howieson in line for a multi-million payout.

Other shareholders in the Stirling-based business including Crawford Gillies, chairman of Scottish Enterprise, also look set to net big returns on their investments in Cascade.

Scots investment houses Panoramic Growth Equity and Braveheart Investment Group had significant stakes in the business.

The company, has been bought by Emerson a listed American business, in a deal that reflects strong overseas interest in Scots technology firms.

Cascade has developed technology that can be used to detect gas leaks and explosives.

The business was spun out of Strathclyde University by a team led by Mr Howieson, who has said its technology offers a much faster and more reliable way of detecting gases than others.

It can identify gases from unique fingerprints detected by the lasers.

The company's technology for detecting explosives has been trialled successfully at Glasgow airport.

Emerson's move follows a period of rapid growth at Cascade Technologies, which has built up an international customer base that includes blue chips such as BP.

The company posted a £1 million profit in the year to March after recording a big increase in sales boosted by its success overseas.

Cascade Technologies grew turnover to a record £6.1m from £3.5m in the preceding year.

Around 85 per cent of sales are generated overseas. Europe, Asia and North America are major markets.

In July Mr Howieson said the company was on track to grow annual sales to in excess of £8m.

He said the firm's success had already put it on the radar of other potential buyers. Mr Howieson said Cascade had had a number of approaches and confirmed these included a bid valuing the company in the millions.

Details of the deal with Emerson were not disclosed.

However, a market source said the valuation put on Cascade was in the region of £40m.

The latest annual return submitted by Cascade Technologies Holdings shows the company had around 2 million shares in issue on 10 September.

Mr Howieson had 139,387, around 7 per cent of the total. This would indicate his stake was valued at around £3m by the deal.

Mr Gillies had 4,226 shares, around 0.2 per cent of the total.

Ivor Tiefenbrun, founder of the Linn Products audio technology firm, had 3,322.

A fund managed by Panoramic Private Equity had the biggest holding, 738,699 shares, around 40 per cent of the total. A £40m deal would value a shareholding of that size at £16m.

Panoramic Growth Equity invested £1.7m in 2011.

Stephen Campbell, a partner at Panoramic, said: "This is an example of UK manufacturing at its best. We are very proud to have given this business the financial and operational support that it needed to achieve such impressive growth over the last three years, becoming a truly international player with market-leading products."

Mr Howieson said Panoramic had provided invaluable help in growing the company in international markets and tripling revenues in the last three years.

He added: "We very much look forward to the next chapter under the watch of our new owners, Emerson."

With headquarters in St Louis, Emerson has approximately 115,000 employees based at 220 manufacturing locations worldwide.

Braveheart Investment Group appears to have more than doubled its money on its investment in Cascade.

Perth-based Braveheart said it had received a net cash consideration of £389,655 for its minority shareholding in Cascade. The company acquired the shareholding in 2006 and in 2008, investing an aggregate of £149,969.

The company said around 40 of its private clients also realised their shareholding in Cascade and most should benefit from the tax reliefs provided by the Enterprise Investment Scheme (EIS).