Contracts finalising the merger of Volkswagen and Porsche will be delayed as the two companies work out a number of details that need to be settled, a VW spokesman told the Financial Times Deutschland.

VW’s CEO and CFO, Martin Winterkorn and Hans Dieter Poetsch, will therefore join the executive board of Porsche somewhat later than thought, the spokesman added. It was originally planned for the two managers to assume the duties of Porsche’s ex-CEO Wendelin Wiedeking and former CFO Holger Haerter in the middle of this month.

The merger contracts have to be signed by Winterkorn and Poetsch in their capacity as VW managers. On behalf of Porsche, the contracts will be signed by current CEO Michael Macht and deputy CEO Thomas Edig.

VW works council head Bernd Osterloh told Reuters the integration of the two companies should not be hurried adding that the merger should take into account the interests of the two carmakers. VW’s financial strength should not be harmed by the incorporation of Porsche into VW, he added.