Part of the Delta group of investment companies, which has links with the Qatari royal family, Delta Two is now the shareholder in the retailer. The Sainsbury family currently owns just 18 per cent of the company in total.
Details of the deal, included purchase price, have not been disclosed, but the share purchase deal is expected to boost calls to split the Sainsbury's property and retail businesses.
The Delta Group has links to property moguls brothers Robert and Vincent Tchenguiz and Robert Tchenguiz has a five per cent share of Sainsbury's and is keen to divide Sainsbury's into separate retail and property arms.
A few weeks ago, a private consortium led by CVC Capital Partners abandoned plans to launch a Â£10.1 billion bid for Sainsbury's.