Nigel Bogle, the BBH group chairman, resigned the account late on Tuesday, and the agency was informed on Wednesday afternoon.
The relationship between BBH and one of its founding clients is understood to have deteriorated in recent times, as the agency struggled to get its creative ideas through to production.
It has not created any work for the brand since the "secrets and lies" TV ad and a poster campaign for Levi’s Originals, both of which launched in 2008.
The network lost its US business to Wieden & Kennedy Portland in 2008 after BBH declined to repitch for the account. W&K launched a US campaign called "ready to work" for the brand in June.
BBH's 1985 "launderette" ad, starring the model Nick Kamen and featuring the Marvin Gaye track 'I Heard It Through The Grapevine', is largely credited with turning around the fortunes of the jeans manufacturer in the 80s.
Other iconic Levi’s ads include "creek" and "Flat Eric".