Shares in the UK's third largest supermarket group Sainsbury's have soared in morning trade after a 14% stake in the company changed hands in a single transaction.

Some 250m Sainsbury's shares were sold at 575 pence (US$11.52) each, sparking rumours that a takeover bid could once again be on the cards. It is also thought that the deal could increase pressure on the supermarket operator to unlock the value of its property portfolio in order to increase returns to shareholders

Investment group Three Delta is thought to be behind the buy, although the firm declined to confirm the rumour when approached by just-food this morning (25 April).

Three Delta focuses on asset-backed business acquisitions and direct real estate opportunities. It is owned by Paul Taylor who has links to property tycoon Robert Tchenguiz. Taylor was formerly chief executive of Tchenguiz's Rotch Property Group/Consensus.

Tchenguiz, who already owns a 5% stake in Sainsbury's, wants to see the supermarket reorganise its business by unlocking the value of its property and possibly dividing into two separate property and retail units.

If Three Delta has snapped up a 14% stake in the retailer, collectively Three Delta and Tchenguiz would control more share capital that the group's largest stakeholder, the Sainsbury's family.

With the Sainsbury's family using its 18% stake to block a recent failed takeover bid and opposing any large-scale property sale, the shift in power could potentially have far-reaching consequences for the group's future ownership and business strategy. 

Earlier this month, a private equity consortium led by CVC Capital Partners abandoned its takeover ambitions when Sainsbury's rejected an offer valued at GBP10.01bn.

Sainsbury's shares rocketed on the news, increasing by 7.08% to 567.5 pence at 1pm (GMT) today.