DUBAI- Qatar Investment Authority (QIA), the biggest shareholder in J Sainsbury Plc, was aware of merger talks between the British supermarket chain and rival Walmart Inc's Asda WMT.N and is supportive of the discussions, a source familiar with the matter told Reuters.

Sainsbury's statement regarding the discussions on Monday will reflect QIA's position on the matter, the source said.

Sainsbury's declined to comment on Sunday.

QIA, which ranks among the top 10 sovereign funds in the world, has a 22 percent stake in Sainsbury's which said on Saturday it was in advanced discussions regarding a combination of the UK's No. 2 and 3 grocers. 

(Reporting by Saeed Azhar and James Davey; Editing by Elaine Hardcastle) ((Saeed.Azhar@thomsonreuters.com; +971 44536787; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))