Securicor is poised to raise £167m (€246m) by offloading its stake in a parcels and logistics joint venture to German postal operator Deutsche Post.
The business, which includes Securicor Omega Express, is deemed surplus to requirements as the group looks to focus on its core security activities.
Securicor chief executive Nick Buckles said the proceeds would be put towards investing in other businesses, including cash services and manned security.
He added: "This disposal represents another significant step towards Securicor's goal of becoming a global top three provider of security solutions."