Northern Light and White Light, based in Edinburgh and London respectively, were both formed in 1971 - the same year in which the UK and Ireland switched to decimal currency - and are planning a joint celebration to mark 40 successful years of serving the technical requirements of the entertainment industry.
Bryan Raven, managing director of White Light, said: "Where better to hold a celebration of our 40th anniversaries than during the ABTT Theatre Show? The whole industry turns out for this annual event and it's an ideal opportunity to buy them a drink to celebrate our birthdays."
Colin Cuthbert, managing director of Northern Light, added: "Make mine a double, Bryan."
The companies are trying to fit in with the whole social whirl of this industry week in London, so the joint celebration will take place straight after the show closes on the Wednesday evening in The Greencoat Boy.
Both companies will distribute drinks vouchers to customers and partners from their respective stands at the ABTT Theatre Show on Wednesday 15 June.
Though technically competitors, the two companies enjoy a long-lasting friendship and working relationship which has its roots with company founders John Simpson of White Light and John Allen of Northern Light and which is continued by the current MDs.
Bryan Raven commented: "Since 1971, White Light and Northern Light have worked together, been customers of each other and bid for the same work too. Throughout it all, a sense of camaraderie and being 'in it together' has prevailed. I look forward to enjoying a similar relationship for the next 40 years."
Colin Cuthbert concluded: "We are fortunate to work in an extremely affable industry, where even 'competitors' can join forces when there is something to celebrate. Our long-standing relationship with White Light means that I'm delighted to be in the position of toasting their success, as well as that of my own company."
(Jim Evans)