Shares of the company were up 3.5% at 422.4 pence.
Retail industry veteran Gresham was appointed as interim chief financial officer in May, after the return of founder Julian Dunkerton to the company sparked the resignation of most of its board and also the former CFO.
In April, Dunkerton was voted back on the board by a slim margin and hours later was named interim chief executive officer with the backing of shareholders looking for a revival of the fashion group's fortunes.
The company has been struggling to expand beyond its sweatshirts, hoodies and jackets and with falling demand in its wholesale and ecommerce business.
"Nick has made a great impact since joining Superdry in an interim capacity," Chairman Peter Williams said on Tuesday, adding that, Gresham was playing a crucial role to ensure that the business is on a stable financial footing.
(Reporting by Sangameswaran S in Bengaluru; Editing by Shinjini Ganguli)