TRANSPORT tycoon Sir Brian Souter has hailed the performance of his family investment office, which he reckons has become one of the most active private equity operations in Scotland.

Sir Brian noted Souter Investments had generated an annual return of 14 per cent in the period since he established it late in 2006, using some of the wealth he amassed after founding Stagecoach with his sister Ann Gloag.

With shares of UK stock market listed companies generating an annual return of six per cent over the period, Sir Brian said he was proud of what Souter Investments has achieved against a difficult backdrop.

The business made its first investments shortly before the credit crunch led to a global financial crisis, which triggered a deep recession.

“An annual return of 14 per cent compared to 6 per cent may not sound like much of a difference but the compounding effect over time means that our portfolio is 180 per cent higher than it would have been had we invested in the UK stock market,” said Sir Brian.

He added: “We are now one of the most active private equity houses based in Scotland, and certainly one of the most active overseas.”

Souter Investments has retained a core holding in Stagecoach, controlling around 14 per cent of the shares in the Perth-based transport group. This is worth around £173 million based on Stagecoach’s current share price.

However, Souter Investments has increased its exposure to unquoted investments significantly over the years.

The firm said it made 15 substantial private equity investments in a range of sectors including health care, consumer goods, oil and gas and financial services in the three years to 31 March.

High profile additions to the portfolio include the Clive Christian luxury fragrance business, acquired in September last year with a consortium that included private equity star Jon Moulton.

In June the firm acquired an interest in the Ashtead Technology subsea engineering business alongside Middle Eastern investors.

The decision to back a company focused on the oil and gas industry amid the crude price plunge suggested Souter Investments will take a long view.

Regarding the Brexit vote, managing director Andy Macfie said: “It’s difficult to predict the impact on individual companies but it could look to increase our appetite to invest in the UK.”

The Scottish firms in the portfolio include Alexander Dennis. The Falkirk bus builder was bought out of administration in 2004 for £90m by Sir Brian and Ms Gloag, former Rangers owner Sir David Murray and merchant banker Sir Angus Grossart.

Successful exits achieved in recent years included the sale of a stake in esure when the insurance firm floated in 2013.

The business has invested around £250m in its portfolio of 30 unquoted firms, which include transport operations in Poland and New Zealand.

Sir Brian said the portfolio is in a healthy state. He is confident Souter Investments will continue to generate superior returns.