Following an exemption granted by The Netherlands Authority for the Financial Markets (AFM), the period has been extended until one week after competition clearances have been obtained from regulators, the European Commission and the Chinese Ministry of Commerce.
The clearances are not expected to be issued before the end of the current offer period on 9 November. The latest extension will see the offer period end no later than 28 February 2013.
Last month the European Commission issued UPS and TNT Express with its statement of objections, part of a competition review of the proposed merger.
The parcel firms expect the merger to be completed in early 2013.