Dutch express package delivery company TNT Express NV says its chief executive has resigned.

TNT is in the process of being acquired by United Parcel Service for $6.77bn, pending negotiations with European regulators.

TNT is Europe's second largest delivery company behind DHL.

Marie-Christine Lombard will quit work by the end of this month "to pursue an external career opportunity," the company said in a statement.

Chief Financial Officer Bernard Bot will take her place as interim CEO, the company said.

TNT repeated it expects its takeover by UPS to be completed by early next year.