Scytale provides communication security software and works with a range of government agencies in the defence and cyber-security space. The Baltimore-based business employs 20 staff and is being acquired from its two founding directors, who will remain with the business.

Douglas Caster, chief executive of Ultra, said that the deal would strengthen the company’s position in the cyber-security market as well as provide synergies with its defence IT subsidiary, ProLogic.

In the six months ending June, Ultra reported an increase in revenue of 40 per cent to £325.5 million, while pre-tax profits were up 171 per cent to £62.9 million.