Phones 4U has confirmed that marketing director Jim Slater is to leave the business.
The company said his departure was scheduled for the end of this month.
A statement said: "We can confirm that Jim Slater, Phones 4u marketing director, is leaving the business at the end of August.
"We would like to thank Jim Slater for his contribution to the business over the last four years and wish him well for the future."
An announcement on a successor will be made in due course.
Managing director David Downie also left the business earlier this year.