There are, however, likely to be performance-related clauses in the deal which would enable Vettel to leave the team before the contract's full duration - just as he did three years ago when he left Red Bull to join Ferrari.

"We discussed briefly once with him but the more the competitive the Ferrari goes the less the reason he would to leave," Mercedes non-executive chairman Niki Lauda told Sky Sports F1 .

However, paddock interest is set to focus on the length of Vettel's new deal with Ferrari given the likelihood the market could be transformed for the 2019 season when Red Bull's Daniel Ricciardo will become a free agent.

In the shorter term, Vettel's extension - and the anticipated Bottas renewal - leaves Fernando Alonso still unable to find a seat at F1's top table as the Spaniard, out of contract with McLaren at the end of the year, prepares to consider his future in the sport.

Renault, who also have a seat available for next season, could yet emerge as another option for Alonso with Robert Kubica and Carlos Sainz among the contenders to replace Jolyon Palmer if the Englishman is dropped.