Red Bull Racing looks set to continue using Renault engines in the 2010 season, after ruling out a possible switch to Mercedes power units.
The Milton Keynes-based squad was chasing the German engines for next season and its hopes of reaching a deal were boosted when F1 rules changed to allow a manufacturer to supply units to four teams.
The delay in reaching a deal, however, has been one of the main reasons why Red Bull now is set to continue with Renault for another year.
The team also believes the Renault unit will be strong next year, when refueling will be banned.
"Since Monza, Renault have remarkably raised their game and done everything they could for us to have such a strong finish of the year", said team boss Christian Horner.
"Renault has fuel-efficient engines which will be very important in 2010."
Mercedes boss Norbert Haug said over the Abu Dhabi Grand Prix weekend that his company was still discussing the viability of supplying another team.
"The approval is there for one year, and it is still in discussion internally. There is no final decision taken," said Haug, who insisted a team could do a good job despite a late decision on engines, as shown by Brawn this year.
"This is probably not the ideal scenario but one thing for sure is that the current world championship winning team got the engine later, and we are not delaying the process," Haug added. "One thing that is proven is that it is possible to get the job done even with a later decision."