Jean-Eric Vergne has confirmed that he will not race with Toro Rosso in 2015.
Vergne joined Toro Rosso at the start of 2012 but was replaced for next year when the squad originally announced a line-up of Daniil Kvyat and Max Verstappen in August.
But Sebastian Vettel's departure from Red Bull enabled Kvyat to be promoted to the senior team and allowed Vergne a chance of a reprieve.
The Frenchman remained in contention for a seat with Toro Rosso in 2015 but, after indicating to French media in Abu Dhabi last weekend that he would not remain with the squad, he has now confirmed his exit from the Italian outfit.
"Despite a good season & 22 pts, I'll not drive anymore for Toro Rosso in 2015," Vergne posted on his official Twitter page.
"Thanks for those years. Let's go for another big challenge."
Formula Renault 3.5 champion Carlos Sainz Jr, who tested for Red Bull on Tuesday, is the front-runner for the seat.
GP3 Champion Alex Lynn and FR3.5 runner-up Pierre Gasly remain in contention.