The sportswear giant informed the IAAF of its decision - understood to be a direct result of the doping scandal sweeping the sport - earlier this week.
Sources have told the BBC the move will result in tens of millions of dollars in lost income to the IAAF.
It is sure to come as a major blow for embattled president Lord Coe.
Neither Adidas nor the IAAF - the International Association of Athletics Federations - have made any comment.
The BBC understands that Adidas informed the IAAF in November it was considering ending their relationship early after a report detailed claims of "state sponsored doping" within Russia.
The BBC understands that Adidas informed the IAAF in November it was considering ending their relationship early after a report detailed claims of "state sponsored doping" within Russia.
The report was compiled by an independent commission set up by the World Anti-Doping Agency (Wada).
Earlier this month, the commission's chairman, Dick Pound, delivered a second, damning report that revealed "corruption was embedded" within the IAAF under former president Lamine Diack.
Within days, a decision at the highest level in Adidas was taken to terminate the relationship with the IAAF.
It is understood the German multinational believes the doping revelations in Pound's reports constitute a breach of its agreement with the IAAF.
The 11-year deal was signed in 2008 and due to run until 2019. At the time it was signed, it was reported the deal was worth $33m (£23m).
But sources have told the BBC that the figure is much higher, as much, in terms of cash and product, as about $8m (£5.6m) per year.
This means the projected lost revenue for the IAAF over the next four years will be more than $30m (£21m).
(BBC News)
Related Articles
IAAF: Lord Coe backed despite damning report of athletics body
Russia ruled in breach of Wada code
IAAF provisionally suspends Russia
