JOHANNESBURG, Sept 7 (Reuters) - Raymond Ackerman, who founded Pick n Pay from just four stores 56 years ago and turned them into one of South Africa's leading grocery retailers, has died aged 92, the company said on Thursday.

The cause of his death was not disclosed in an emailed statement.

"It is with profound sadness that we announce the death at the age of 92 of visionary South African, and founder of Pick n Pay, Raymond Ackerman," the company said.

The retail legend came from a retailing family; his father Gus founded Ackermans clothing group after World War 1. The Ackermans retail group was later sold to competitor Greatermans, which started the supermarket group Checkers, now part of bigger rival Shoprite.

It is at Greatermans where Ackerman started his career in retail, when he was also put in charge of launching the Checkers supermarkets.

After leaving Greatermans, Ackerman bought four small stores in Cape Town trading under the name Pick 'n Pay. By the time Ackerman retired in 2010 and handed the chairman's reins to son Gareth, Pick n Pay was operating 20 hypermarkets and 402 supermarkets across South Africa, with a group turnover of almost 50 billion rand ($2.60 billion).

Today it generates 106 billion rand in annual turnover and owns more than 2,000 stores across South Africa and seven other African countries.

Ackerman was known for his many campaigns against monopolies and price-fixing in his active retail days and also introducing the hypermarket concept to South Africa.

"He was an enduring optimist about South Africa’s future, and his passing leaves a great void for us all," the company said. ($1 = 19.2601 rand) (Reporting by Nqobile Dludla; Editing by Christina Fincher)