TransportHub combines Polestar's software platform for timetable, marketing and passenger information collateral production with Fabrik's creative skills and transport strategic thinking.
Both companies and their teams have been successful suppliers to the transport sector for more than a decade.
Rachael Woods, managing director of Fabrik Communications, said: "The team at Fabrik is delighted to be joining forces with Polestar and relish the opportunity to build and continue on their success to date."
Ian Allan, head of new media at Polestar Group, said: "Polestar is really looking forward to working with Fabrik. We believe that our new joint team will provide unparalleled service and firepower to the transport sector.
"This is one of several exciting developments in 2014 building on the continuing development of Polestar’s digital and technological foundation."