Niki Lauda is heading to Australia denying rumours that Mercedes are lining up a tilt to sign Sebastian Vettel.

The German team does not deny that Nico Rosberg's successor, Valtteri Bottas, was given a mere one-year deal so that a bigger name might be signed up for 2018, but F1 legend Lauda does deny that the big plan is to lure German Vettel from Ferrari.

"That is not our plan - I must say that quite clearly," the triple world champion and Mercedes team chairman told the Austrian broadcaster ORF.

"We're going to start with Bottas and [Lewis] Hamilton and see how it goes."

The season-opening Australian Grand Prix takes place this Sunday.