The purchase will help the media organisation bulk up its newly-formed OOH division, Global Outdoor.
Exterion Media operates in the United Kingdom, Ireland, France, the Netherlands and Spain. In the UK, it boasts an estimated 20% share in the sector, and holds the lucrative £1.1bn Transport for London (TfL) advertising contract for the London Underground and rail networks.
Current chief executive Leon Taviansky will transition with the business to Global Outdoor, which it has been announced will be overseen by Stephen Miron, Global’s group chief executive.
Miron said the acquisition complemented its two most recent buys.
"The incredibly positive reaction we have had to the news of our entrance into the OOH sector only reaffirms our belief and excitement about the opportunities within the outdoor market," he said.
"Exterion has a great track record in the UK and across Europe and we look forward to working with the team to develop the business further."
'Heavily investing' in digital sites
The LBC, Heart and Smooth Radio owner now has three prime OOH estates that will help it flex its muscle against giants like JCDecaux and Clear Channel.
Global previously suggested that digital OOH will become an increasingly important part of its business, saying it would "heavily invest" across Primesight and Outdoor Plus' portfolio to up the number of digital sites it owned.
The announcement comes as advertisers – such as Burger King – are looking to experiment with digital OOH as a way to connect the dots between what consumers are doing online and what they're doing on their way to work or socialising.
On the radio side, Global has already doubled down on programmatic with its audio exchange platform DAX.
When Exterion won the TfL contract in 2016 the business told The Drum it believed its digital prowess could help it compete with the likes of Facebook and ITV to help the public body generate as much as £3.4bn in commercial revenue by 2023.
The 'perfect fit'
Exterion is also responsible for the OOH inventory across the other three metro systems in the UK: Newcastle, Liverpool and Glasgow.
The company claims to be the largest supplier of bus side advertising in the UK, and Global said its "transport focussed assets" would serve as a "perfect" complement to the portfolio it scooped up in the Primesight and Outdoor Plus deal, adding transport to its "existing, mostly roadside business."
Primesight has an OOH ad estate of billboards and display panels that covers more than 35,000 sites in the UK, claiming to reach 95% of the population.
Outdoor Plus, meanwhile, owns a multitude of premium digital ad sites nationwide, especially in London where it owns the space at the Hammersmith Towers and Euston Underpass.
Global's most recent purchase will have a far-reaching impact on the OOH industry for both competitors and brands.
Ashley Tabor, founder and executive president of Global, hinted at the end-to-end possibilities the group can now offer clients, saying "we now have credible solutions on air, online and outdoor".
He added: "The Exterion Media inventory also affords many opportunities and synergies with our current business and we look forward to bringing new innovations to the OOH sector for the benefit of advertisers."
Leon Taviansky, chief executive at Exterion, said: “Like many others I was very impressed to see Global enter the OOH market and can fully understand why Exterion Media sits very well within Global’s OOH portfolio. We look forward to joining the Global family.”