A previously announced Memorandum of Understanding between Daimler Truck, Mitsubishi Fuso, Hino and Toyota is being held up by delays in regulatory approvals.

Announced last May, the MoU would see the manufacturers work together on accelerating the development of advanced technologies, while merging Mitsubishi Fuso Truck and Bus with Hino. That merger was set to be signed by the end of this March with integration completed by the end of this year.

But in an update today, the companies announced “The process of obtaining necessary regulatory clearances and approvals under competition and other laws and regulations, as well as the pending investigations related to Hino’s engine certification issues, are still ongoing. As such, the original schedule has been extended.”

They did not provide a new timeline for the equal footing merger to be completed. However, they did indicate the merger discussions are “progressing on a positive note.”