Infa operates three facilities, Labochim and Sifavitor in Italy and Derivados Químicos in Spain, and employs 400 people. The firm makes active pharmaceutical ingredients (APIs) for generic drugs.
The Sifavitor site is also home to an R&D centre dedicated to the development of generic APIs for respiratory diseases.
A spokeswoman for Infa Group told us: "The two companies are complementary" adding that Olon would be taking on all staff and existing supply contracts.
The takeover will give Olon a portfolio of about 130 Active US Drug Master Files (DMFs) and more than 50 EU Certificates of Suitability (COS) or Compliance with the European Pharmacopoeia (CEP).
Olon is owned by Italian chemical firm P&R Group, which finished dosage drug firm Fidia Farmaceutici, patch delivery technology developer Biofarmitalia and chemical manufacturer SIR Industrial.
Olon, which generated revenue of €200m ($224m) in 2015, predicted that the merged company would see sales of more than €300m this year.