Gemalto NV of Amsterdam has increased its capital investment to become the majority shareholder in the French mobile-payments firm Netsize.
Gemalto did not say exactly how big its stake is now.
The Dutch company has an option to buy the rest of the company at a later date.
Previously, Gemalto held a 24% stake in Netsize, which offers mobile-payment services for 100 mobile operators in 28 countries.