The Rev Peter McConnell had denied inappropriately touching the stranger during a transatlantic flight between Philadelphia and Heathrow in March 2017.
The 63-year-old, of St Helen's Church, Longhorsley, Northumberland, had been on trial at Newcastle Crown Court, having pleaded not guilty to a single count of sexual assault.
Jurors were sent out to start their deliberations on Friday morning, but were discharged by Judge Nolan QC in the afternoon.
Prosecutor Andrew Espley said he was unsure whether a retrial would be sought.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.
