article: The Australian - one of the most highly regarded drivers in Formula 1 - is known to have been interesting Ferrari. Ferrari driver Kimi Raikkonen is out of contract at the end of this season and the Italian team are weighing up whether to retain the 36-year-old Finn. Ricciardo said at the Austrian Grand Prix that he would stay at Red Bull, which he believed was "the best place to be next year to challenge Mercedes". Ricciardo, who is 27 on Friday, has been buoyed by progress with the Renault engine, which now has a much reduced performance gap to Mercedes than it did for the last two seasons. Ricciardo signed his new Red Bull contract to the end of 2018 after his breakthrough season in 2014, when he was promoted to the senior team from Toro Rosso and beat four-time world champion Sebastian Vettel. The German moved to Ferrari at the end of that season. Ricciardo's Red Bull deal is said by insiders to have no opt-outs or break clauses, but having a contract in F1 does not necessarily mean a driver will stay with a team. However, his remarks clearly rule him out of Ferrari's thinking for next season. Ferrari are not expected to fully address the issue of a partner for Vettel next year until after next weekend's British Grand Prix at the earliest. Raikkonen has a decent chance of being retained, but other drivers in the frame are Force India's Sergio Perez and Nico Hulkenberg, Toro Rosso's Carlos Sainz, Williams' Valtteri Bottas and Haas' Romain Grosjean. Ferrari had also been interested in Max Verstappen, but the 18-year-old Dutchman is under contract until the end of 2019 and Red Bull intend to have him and Ricciardo as their line-up for the foreseeable future. On Wednesday, Red Bull said they had taken up their contractual option on Sainz and that he would be staying at their junior team Toro Rosso in 2017. However, Red Bull motorsport adviser Helmut Marko has said he would be willing to talk to Ferrari about releasing him if they expressed an interest and offered to buy him out. Perez's candidature is being pushed by Mexican billionaire Carlos Slim, who is on the board of the team's main sponsor, the tobacco giant Philip Morris. Subscribe to the BBC Sport newsletter to get our pick of news, features and video sent to your inbox.
summary: Daniel Ricciardo says he will stay at Red Bull until the end of 2018.