Multiple industry sources told Campaign that they believe that Outdoor Plus, which is led by founder Jonathan Lewis, is close to agreeing a deal but they did not identify a buyer. Outdoor Plus declined to comment.
Industry insiders say Outdoor Plus has been looking at its options after rival Ocean Outdoor announced in March that it plans to float on the London stock market and grow "through consolidation".
The company has not appointed an external corporate finance firm to advise on its options. However, it is able to draw on the expertise of Inflexion Private Equity, which took a large, minority stake in 2016.
Global, Britain’s biggest radio group, declined to comment on the speculation that it has talked to Outdoor Plus.
People familiar with the radio sector suggested the media and entertainment group, which owns Capital, Classic, Heart and LBC, looks at a lot of potential M&A deals at any one time.
Analysts have described the out-of-home sector as ripe for consolidation and it has begun attracting interest from a wide range of buyers, including tech companies such as Netflix and Google.
Outdoor Plus has invested heavily in digital OOH screens, chiefly in London, such as The One Knightsbridge on the Hyde Park underpass and the Euston Underpass, and has sold off most of its traditional billboards in recent years.
Turnover was £30.5m last year, according to accounts for parent company Project Iconic Holdings.
That makes Outdoor Plus about number six in Britain’s near-£1bn-a-year OOH market behind larger firms such as JC Decaux, Clear Channel, Exterion Media, Primesight and Ocean Outdoor.
Outdoor Plus could be worth over £60m, based on an estimate of double annual revenues. The company has an eclectic and starry list of about 40 small shareholders, who include Nick Mason, the Pink Floyd musician, and Phil Georgiadis, chairman of Blue 449, as well as Lewis and other Outdoor Plus staff, according to company filings.
When Inflexion Private Equity bought a large, minority stake in 2016, it appointed Nigel Sharrocks, formerly of Dentsu Aegis Network, as non-executive chairman of the OOH firm.
A tie-up between Outdoor Plus and Global would be a surprising move but would allow the radio group to expand in a new sector as it faces regulatory hurdles in its core market.
Global, which is owned by the Tabor family and already has more than a 50% share of UK commercial radio, has been expanding in new areas, including programmatic audio platform DAX and music festivals.
Outdoor Plus and Global have worked together in the past on campaigns, including a partnership with Universal Music that involved linking Justin Bieber songs on Capital FM with creative that appeared in real time on digital OOH screens.
Global said at the time: "We’ve seen that digital OOH gets commuters to tune into Capital."
If Global were to move into OOH, it would not be an unprecedented step. Clear Channel’s parent company, iHeart Media, the US media giant, also owns radio stations in the United States.
However, several executives working in OOH cautioned that the opportunities for "cross-selling" across radio and out of home were "limited".
All of the leading UK OOH firms, with the exception of JC Decaux, have private equity owners.
Ocean Outdoor told the London stock market this week that its plan to float later this year is "progressing well" and access to capital should drive "new growth opportunities and future acquisitions".
Netflix bought 35 billboards in Los Angeles from Regency Outdoor in July and Google has been looking to invest in digital OOH in Germany as programmatic trading will allow targeting and buying on an automated, real-time basis.