Bosses at a Burton-based global engineering giant have forecast a growth in sales from its "substantial" order book – despite racking up pre-tax losses of £91.8 million.

Doncasters Group, which operates out of a site in Centrum 100, revealed that losses had widened and debts had mushroomed following the fall in the value of the pound since last year's EU Referendum.

The company acknowledged that the weakening of sterling against the dollar had led the overall value of the company's debts to increase by more than £100 million to over £1.2 billion.

Auditor PriceWaterhouseCoopers said the size of the debts posed a threat to the group's ability to continue as a going concern, but added that it expects its performance to improve this year.

Chief executive David Smoot said: "2016 has been a year of positioning for growth through investment and product introduction.

"The group has seen a substantial increase in its order book and a new product pipeline which is expected to lead to growth in sales and earnings in 2017 supported by encouraging market conditions."

The company employs a total of 5,000 people across its division with 32 manufacturing facilities in US, Germany, Belgium, Mexico, China and the UK.

The firm was founded in 1778, when Daniel Doncaster set up in Sheffield using the crucible steel-making process to make hand tools. It is one of the oldest manufacturing companies in the world.

At that time, the father of production engineering, Joseph Bramah, was manufacturing tools which could cut cast and wrought iron, helping make the industrial revolution possible.

The two firms later combined, forming the beginning of the Doncasters Group which has its corporate headquarters in Burton.

The firm, owned by Dubai International Capital since 2006, made a pre-tax loss of £91.8 million during the 12 months to December 31, 2016, compared to £74.6 million 12 months earlier.

However, revenue increased over the same period from £627.8 million to £654.2 million.

The company also said it made "substantial progress" in winning new work, helping boost its order book by 41 per cent during 2016.

The company supplies engineering components for aero engines, industrial gas turbines and other specialist high-performance applications.