Seeger leaves after more than six years in the role and 10 years at GKN. He will step down from the board on 25 February next year and will depart the group on 31 August.
Incoming finance director Walker joins the GKN board on 1 January and will take on his new role officially on 26 February.
Walker currently holds the same position at FTSE 250-listed publishing and events company Informa, a role he has held since March 2008.
“Bill’s financial discipline, strong leadership and commitment have been key factors in the consolidation of the group’s financial strength and the creation of strong foundations for future growth,” said GKN chairman Mike Turner.
“We are delighted that Adam will join the group as Bill’s successor. His wide ranging financial management experience in internationally quoted companies makes him ideally suited for the role at GKN.”
GKN’s shares closed up 4.4 per cent at 358.2p yesterday.