The billing, charging and customer relationship management (CRM) company said it has achieved £13.2mln in new sales in the current financial year on the back of the deal.
Cerillion will supply its enterprise CRM and billing solutions along with the ongoing provision of managed services to the European company, whose name was not disclosed.
The contract is expected to be implemented over the next nine to 12 months.
The company has secured a series of contract wins since it started trading on AIM in March 2016. In December it announced it had secured a €3.3mln contract with a new customer in Europe, a month after saying it had signed a US $2.8mln deal in the US.
Spun out of the tech giant Logica in 1999, Cerillion has grown into an international business with 75 customers in 40 countries.
For the year ended 30 September 2016, the group reported a 4% increase in annualised adjusted pre-tax profit to £2.3mln on a 6% increase in revenue to £14.8mln, driven by software sales.
Shares rose 0.54% to 225.0p in morning trading.