By Alan Baldwin
MONACO (Reuters) - Red Bull completed their reconciliation with Renault on Sunday by announcing that they and sister team Toro Rosso will use Formula One engines provided by the French manufacturer in 2017 and 2018.
Red Bull currently use Renault power units with Tag Heuer branding and that will stay the same.
The energy drink brand's Italy-based junior team Toro Rosso were powered by Renault last year but agreed a deal with Ferrari to use their 2015 engines this season.
Red Bull said Toro Rosso could change the name of their Renault engines if they wished to do so as part of the new agreement.
"We are delighted to extend our partnership which has proved very successful over time," said Red Bull team principal Christian Horner in a statement at the Monaco Grand Prix, where his Australian driver Daniel Ricciardo qualified on pole position for the first time.
"After the reconstruction that Renault has undertaken, clear progress has been made which has made it logical to continue with the TAG Heuer badged engine."
Red Bull and Renault first partnered in 2007 and won four successive drivers' and constructors' championships with Germany's Sebastian Vettel between 2010 and 2013, as well as 51 grands prix to date.
The relationship fell apart with the introduction of the new V6 turbo hybrid engine formula in 2014, with Renault's offering both unreliable and uncompetitive.
The partners appeared to have reached breaking point last year, when Red Bull tried to find an alternative supplier and warned they might quit the sport if they could not secure a competitive engine.
They ended up with a compromise deal, after failing to find another source, staying with Renault but with the engines renamed after their Swiss watchmaker sponsor.
Renault, who now have their own works team after buying failing Lotus, have made big steps with the power unit since then and 18-year-old Dutch driver Max Verstappen won the Spanish Grand Prix on his Red Bull debut two weeks ago.
Ricciardo has a new specification engine in Monaco that Renault estimate could offer half a second a lap in performance at some circuits.
"We are very pleased to partner with two such strong teams as Red Bull Racing and Scuderia Toro Rosso," said Renault Sport Racing president Jerome Stoll in a statement.
"Having competitive partners demonstrates the confidence both have in the improved Renault power unit and in our organisation as a whole."
(Editing by John O'Brien)