Revenues during the six-month period to September 26 came in at £252.2m, a 3.1% increase over the same period last year, while operating profit across the group was up 17% to £51m before exceptional items.

However, pre-tax profit fell 6.4% to £44.2m on sales that were up 3% to £252.2m.

The group, which prints notes in more than 150 currencies, cited the value of sterling against the US dollar and euro as a contributing factor to its results, adding £14m to revenue and £4m to its operating profit.

Brookes said: "The group has delivered a strong performance, reflecting the successful execution of our focused strategy, our ongoing drive for productivity improvements and the resilience of our key markets.

"The signing of the 10-year UK Passport contract during the period demonstrated De La Rue's continuing capability for generating long-term profitable growth."

Cash generated in the first half of the year was £32.2m, while the group closed the half year with net debt of £53.4m, up from £33.1m at the beginning of the financial year.

Looking forward to the printer's full-year results, Brookes said the board remained confident .