According to BusinessF1, sources close to Marko have confirmed the existence of this approach.
They report that Marko 'politely' declined the offer, expressing his commitment to Red Bull and stating that he is 'going nowhere'.
Marko is said to be wary of such approaches, suspecting that they are more interested in his knowledge of Red Bull's operations than in his expertise.
Having spent his entire Formula 1 career with Red Bull Racing and feeling a deep personal loyalty to the late Red Bull owner Dietrich Mateschitz, Marko's associates believe he may retire from the sport completely once his tenure with Red Bull Racing comes to an end.