The company, which last month bettered market expectations with a 35 per cent jump in annual profits, is to appoint The Hogarth Partnership as its retained financial comms agency from next month.
Domino's finance director Lee Ginsberg, who joined the company from Holmes Place six months ago, told PRWeek he had not invited Buchanan to pitch for the business and had held talks with four agencies over the past few months.
Ginsberg ruled out a Domino's move to the London Stock Exchange's main market, but declined to comment on acquisitions in the near future.
Founded in the US in 1960, Domino's now operates through largely autonomous subsidiaries, selling the franchises for stores in 50 countries.
Of the company's 7,500 stores, there are 2,000 franchisees.
Buchanan worked on the 2000 AIM listing of Domino's Pizza UK & IRL, which now has 370 stores and more than149 franchisees.
Earlier this month the company reported an 8.2 per cent rise in like-for-like sales for the 15 weeks to 17 April. Chief executive Stephen Hemsley said at the company's recent AGM that there was room for further growth as only 40 per cent of households had convenient access to a Domino's store.
Meanwhile, the group reported a £2.3m jump in pre-tax profit to £8.8m for 2003.