The phrase "adjacent industry" is correct and usable in written English. You can use it to refer to an industry that is closely related to another, either geographically or in terms of the products and services it provides. For example, "The automotive industry and the adjacent aerospace industry have seen a steady increase in demand in recent years.".
"Whenever you bring someone in from the outside in an adjacent industry, you never know," said Jeffrey L. Bewkes, chief executive of Time Warner, Time Inc.'s parent company.
Developments in personalized medicine and the unique nature of the human microbiome offers an opportunity for Big Pharma to develop devices that no adjacent industry has the expertise to develop.
"Adjacent industries are moving into this industry," Sarin warned in February.
Firms had to sprawl into adjacent industries to grow.
And it is making enemies in its own and adjacent industries.
Merlin is pioneering the fusion of IP based 'content' between screen and location based entertainment, through symbiotic relationships with global leaders in adjacent industries, from LEGO IP extension with Warner Bros Ninjagoo), DreamWorks (Shrek/Kung Fu Panda), Lucasfilm/Disney (Star Wars), to SONY (Ghostbusters) and BBC.
Tencent is instead investing in adjacent industries.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK