One of north-east Scotland's most successful independent businesses, Score Group in Peterhead owned by Charles Ritchie, racked up a huge rise in operating profit last year from £1.1 million to £7.3m.

Mr Ritchie, 65, ranked in the UK's top 100 'rich list' as owner of the £52m engineering empire, has reported turnover jumping from £116m to £150m in the latest accounts just lodged at Companies House.

He writes: "Currently, our order book is at an all-time high. However, the pressure on our overhead shows no sign of abating."

He says the 25% fall in pre-tax profit to £6.5m was due to the previous year's exceptional gain, when Score sold its Pacific business to management for £17.5m, recording a profit of £8m.

The turnover rise was due to a buoyant oil and gas market, Mr Ritchie says, adding that the increase in the employee shareholder base from 719 to 753, out of a workforce which rose during the year from 1283 to 1341, "greatly benefits the daily performance of the business".

Score last October unveiled a new £5m base in Peterhead and said it was on course to create 170 new jobs there.

The report shows that exports rose from £63m to £76m last year, or 51% of sales, while UK-manufactured product at £91m was two-thirds of the total.

Mr Ritchie writes that the group received planning permission for new facilities in Norway, Australia and Cowdenbeath in Fife, and moved into larger facilities in Canada and Trinidad. It had recently spawned Score Diagnostics to develop valve monitoring technologies and had formed a joint venture in Malaysia.

Mr Ritchie highlights Score's work with international navies, developing marine products, and work on key projects by its subsea division, using the largest hyperbaric chambers available in Europe.

He concludes: "This year we have created more patents than in previous years and this trend will continue ... this world is not going to stop any time soon and we are witnessing an acceleration of change."

The highest-paid director received only £282,000 compared with £1.7m the previous year, and the £2m dividend was also cut to nil.