Tuffnells Parcels Express MD Chris Ward is leaving the business following its integration within parent company Connect Group.
Connect Group, which also owns Smiths News, bought Tuffnells in November 2014.
A spokeswoman for Connect Group said Ward, who joined the business in May 2015, will be leaving the business as it moves towards a single leadership team across the whole group.
However, Smiths News MD Jonathan Bunting will remain as chief operations officer for both divisions.
The spokeswoman said there were no plans to integrate physical networks, despite Tuffnells utlising Smiths News vehicles in some of its operations after a trial in Bristol.
She added: "Integration refers to the group’s core businesses working together to offer a seamless combination of services for customers - headed by a single leadership team with responsibility for their combined commercial performance.
"We don’t plan to integrate the physical networks at this stage; any opportunities that may develop over time will be driven by the requirements of serving our customers."
She added that Connect Group CEO Mark Cashmore will be heading up the integrated business.
Tuffnells has been fuelling strong growth at Connect Group since the acquisition.
The integration will take effect from 1 September.
- Read Motor Transport's interview with outgoing MD Chris Ward
