The £78.5m deal for the TMW Unlimited owner is subject only to formal court approval, after which its shares will be de-listed from the London Stock Exchange.
Barrie Brien, Creston chief executive, said: "We’re delighted Creston shareholders have voted overwhelmingly to accept the offer and today’s vote allows our shareholders to realise value from their investment in cash at an attractive premium.
"Furthermore, it offers the business, with the support of Dbay Advisors, an exciting opportunity to continue to grow the Unlimited Group as a private company, which we believe is in the best interests of our clients and colleagues."
Dbay currently owns about 28% of Creston. Announcing plans to acquire Creston last month, Dbay chief executive Alex Paiusco said: "We have been significant investors in Creston for over two years and are excited about this opportunity to help develop the business, alongside its management team and employees, and to fulfil its potential."
Creston non-executive director Nigel Lingwood, who will step down next week along with fellow non-exec Kate Burns, said in November that the decision to sell comes "in light of uncertain market conditions" and "as the business and our clients’ requirements continue to develop".
Creston said the plan is not to make "material changes" to the employment status of staff. On completion, the new owner plans to undertake a full review of the business, which it said "may lead to the identification of additional strategic opportunities for Creston", which will be "evaluated…with a view to optimising Creston’s performance and accelerating its growth".
In October, Campaign reported that the company is to drop "Creston" from its brand to become The Unlimited Group. Creston remains the name of the holding company, while individual agencies will retain their brand name within Unlimited Group.
A version of this article was first published by PRWeek.