Drinks giant Diageo, whose brands include Guinness, has decided to end a near 30-year link with the Exiles club.
“Their recent decision is not consistent with our values and so we have ended our sponsorship,” said Diageo in a statement.
Jackson, 27, is due to sign from Perpignan. He and then Ulster team-mate Stuart Olding were acquitted in March last year of raping the same woman in Mr Jackson’s house in 2016.
A Diageo spokesman said the company was “committed to the highest possible standards” and there was “a series of reasons” for ending the sponsorship.