Talks between Toro Rosso and Honda regarding a Formula 1 engine supply deal for 2018 have collapsed.
Honda is keen to take on a second F1 team, after its agreement with Sauber was cancelled, as it feels the extra data gathered would help development with McLaren.
Talks have been ongoing for several weeks, even though Toro Rosso already has a deal with Renault in place for next year.
But it is believed the two parties could not come to an arrangement regarding the financial aspects of the deal.
With time running short to come to an agreement in order for both Toro Rosso and Honda to be sufficiently prepared for next year, it was decided to bring talks to an end.
Toro Rosso will continue to run Renault power units next season. Had it switched to Honda power, it would have been its third different supplier in three years.
Honda and Toro Rosso were unavailable for comment.
It remains unclear whether Honda will continue with McLaren next season after a challenging campaign so far.
McLaren is evaluating its options, even though Ferrari and Mercedes have made it clear they will not supply engines to the team.
Should McLaren split with Honda, that would force the Japanese manufacturer out of the championship and leave Renault as McLaren's only option for a supply.
Time to agree a deal with Renault is running short, with engineers already advanced in working on next year's car configuration.
It is believed a Renault deal - while not impossible - is unlikely, as the French marque is thought to be reluctant to expand its supply to a fourth team due to concerns it could impact on reliability.