Co-founder Fran Cotton is moving from managing director to executive chairman, taking over from Sir David Jones.
New managing director will be Nick Hamblin, who is promoted from retail director.
Leisurewear brand Cotton Traders plans to open up to 16 new service station shops over the next 12 months, as well as opening 10 stores at garden centres.
Cotton said the expansion would create up to 400 jobs in total.
Cotton Traders currently operates shops at 74 garden centres and employs around 1,200 staff.
"Garden centres has shown to be a good strategy and our shops at motorway services have performed extremely well, leading us to believe we can do a lot more.
"There is huge footfall at services and there is sufficient dwell time to make them a good proposition for us. They are also going a bit more upmarket and establishing themselves as retail venues in their own right, which suits us."
Sales for the year to January 31 are forecast to be £76m, up from £69m with profits flat at about £6m. Revenues for the next 12 months are predicted to reach £84m with underlying profits of £7m.