The Safety Letterbox Company (SLB), a Neath-based manufacturer of lockable mailboxes, has been acquired by German business RENZ Group.
SLB said the deal would strengthen its brand competitiveness in the UK and internationally.
SLB were advised by Gambit Corporate Finance LLP. Gambit partner Frank Holmes commented "Renz will benefit from the anticipated privatisation of Royal Mail and changes to post delivery."
SLB will continue as an independent subsidiary of RENZ Group. Chairman Ian Brown will remain on as a technical consultant and managing director Alison Orrells will continue in her role.
Brown said: "The future of SLB will be further enhanced by the RENZ Group, allowing both parties to share knowledge, products and expertise to provide customers with the total mail delivery package in the future.
"Together we can push the boundaries in mail delivery and product design to provide customers with secure, high quality products for any site profile and budget worldwide."
RENZ Group chief executive Armin Renz added: "SLB has a successful history and has become a strong UK brand with great international potential. RENZ is also a family-owned company so our business philosophies and approach fit well together, in turn creating a solid platform from which to develop new growth strategies for the future."
The Safety Letterbox Company was founded in 1986. RENZ Group was founded more than 80 years ago and has more than 700 employees.