The firm has made the investment in T4 Media and T4 Adbarriers after agreeing a deal with their four shareholders.

T4 Media and T4 Adbarriers markets advertising space on ticket barrier equipment in railway stations and car parks throughout the UK and Ireland.

Octopus has come in as a partner to help finance T4 Media’s growth by increasing revenues and will develop its client list. This strategic development will include further bolt on acquisitions.

T4’s managing director, Marco Pieters, said with Octopus’ backing the board can accelerate the company’s growth.

“We intend to create a leading transport media business, and this funding will support that objective,” he added. “We have been impressed by Octopus’ credentials in the media sector, and the value and experience that they bring to the business.”

Octopus’ investment was led by Alistair Brew, who was supported by Paddy Woods Ballard and Christopher Allner. Post-completion, Allner joins T4’s board with Woods Ballard as an observer. Paul Daniels continues as chairman.

Woods Ballard said the firm has backed T4 due to its management building a market leading transport media business.

“We anticipate making further add on acquisitions to T4 in due course, and believe T4 to be an excellent platform from which to make these acquisitions,” he added.

The vendors were advised on the terms of the disposal by a team from law firm Thomas Eggar LLP, led by partner Michael Crooks, who said the firm was approached due to its existing relationship with the client.

Octopus is a leading investor into fast growing SME companies with over £360 million under management. Octopus specialises in providing £2 million to £8 million of equity finance for management buy-outs, buy-ins and development capital for UK companies in transactions with an enterprise value of typically up to £25 million.

Octopus has been an active investor in the media sector with investments including Gyro, Reading Room, Luther Pendragon, Promotion Space and npi.