The city council is set to to plough in another £200,000 into the main festivals over the next three years in the run-up to a summer of celebrations in 2017.
And the sum is expected to be matched by other public backers, despite the public spending squeeze, following months of behind-the-scenes talks.
It is thought an additional £1 million will be brought to the able by other public backers of the city’s main cultural events, which already get core funding of more than £10 million between them.
The council, which already puts more than £4 million into the festivals, said a “collaborative, cross-agency partnership approach” was being planned to mark the anniversary.
In a report for councillors, Greg Ward, the authority’s economy director, said: “The festivals intend to work with city partners to develop open and innovative programmes, to cultivate young talent, and to bring Scotland to the world and the world to Scotland.”
Details of the deal have emerged after a study warned the city faced slipping out of the premier division of events if current funding levels dropped and new sources of backing could not be found.
The Thundering Hooves report recommended the biggest ever global marketing campaign for the festivals to mark the 70th anniversary, using the model of programmes developed for the London Olympics and the Commonwealth Games.
The report called for “secure funding” to be found for new initiatives, programmes and collaborations for the 70th anniversary which would act as “a national and international moment of collective focus.”
An additional £1 million was secured from various public bodies, including the council, Creative Scotland, EventScotland and the Scottish Government, for Edinburgh Festival programming last year.
The Edinburgh International Festival, the Fringe and the film festival were all launched in 1947 after the city fathers decided to deploy the arts as an antidote to post-war austerity. However the extra money will be ploughed into special anniversary events and new programming elements across all of the main festivals over the next few years.
Richard Lewis, the city council’s festivals and events champion, said: “Artists and visitors from all over the world are looking ahead to 2017 and the 70th anniversary of Edinburgh’s emergence as the world’s leading festival city.
“The Thundering Hooves report emphasised the need for a fitting programme to mark the milestone and there are clear cultural and economic grounds for this.”
The Scottish Government, already ringfences £2.25m a year for an “Edinburgh Festivals Expo Fund.”
Speaking last month, culture secretary Fiona Hyslop said: “As a festival city, what Edinburgh has to look at going forward is how the city maintains and grows its reputation, and attracts more visitors.”