A Scottish firm that supplies electrical equipment for use in hazardous areas has predicted it will increase turnover by about 40% to a record £140 million in the year amid buoyant oil and gas activity levels in the North Sea and overseas.

MacLean Electrical said it was on course to record a £40m rise in sales in the year to March.

The Dingwall-based business forecasts it will double pre-tax profits to £10m in the year, from £5m in the preceding period.

The growth reflects surging investment in the North Sea, where oil and gas firms are trying to ramp up production to meet strong demand.

Operators including BP are investing billions of pounds bringing giant new fields in areas like west of Shetland on stream.

With oil and gas firms also investing heavily in trying to boost output from existing ­facilities, demand for the kind of specialised electrical kit MacLeans supplies is booming.

The privately owned firm was founded in 1974 by John MacLean to target the developing UK North Sea offshore oil & gas market.

It says it has been the leading UK oil and gas industry maintenance, repair and operations supplier of electrical products and cables for several years.

Signalling confidence in the prospects for the North Sea market, MacLean Electrical has invested £1m in extending its warehouse facilities at Altens, Aberdeen.

It has invested a further £1m establishing a new facility in Great Yarmouth, expected to open next March. Oil and gas firms service assets in the southern North Sea from the Norfolk port.

MacLean Electrical has also capitalised on surging spending in oil and gas markets in countries like Australia.

The company's JT Day ­operation in that country is supplying AUS$59m (£34.5m) of equipment such as power, control and instrument cables, for use on the Chevron-operated Wheatstone liquefied natural gas project in Western Australia.

The work is expected to run until 2016.

Group managing director Donnie MacLean said: "Our ­business has been extremely buoyant for several years now, especially in the oil and gas sector, and we see no signs of that situation letting up in the near future."

MacLean also has bases in the USA and Kazakhstan.

The company said its lighting division, which has a base in Cumbernauld, is also on track to achieve strong growth in sales.

MacLean's light and energy design arm is working with local governments, government agencies and consultancies.

Mr MacLean said: "The successes from winning several large contracts this year will be reflected in the results for the forthcoming years. Our core markets are continuing to show improvement and we are ­confident of future growth and successful results."

He said MacLean Electrical would continue to pursue growth opportunities at home and overseas.

MacLean bought the JT Day business in 2007 for an undisclosed sum. Operating profit fell to £5.17m in the year to March, from £6.1m in the previous year.

The company said this was a result of an "extremely successful" 2012, a later than anticipated start on the Wheatstone work, plus investment in its facilities in Aberdeen, Great Yarmouth and Brisbane, Australia. Turnover fell to £98m from £109m.

The company has 166 employees in Scotland and 215 in total.

After adding 16 employees to the payroll over the past year, it expects to hire more staff in coming months.