Miss Sixty UK managing director Steven Peters left the fashion retailer and wholesale business on Tuesday.
Peters began working with Miss Sixty's Italian owners via a distribution agency nine years ago. In January 2001, he was appointed managing director after the division became a wholly-owned subsidiary.
'In the past five years, sales have increased from£6 million to more than£35 million. But I want to go back to working with niche brands, which I think are missing from the UK high street,' said Peters.
There are 275 Miss Sixty UK wholesale accounts and 10 Miss Sixty and Energie stores.