The UK's takeover watchdog has given the private equity consortium circling Sainsbury’s a bid deadline of 13 April.
The consortium - which includes CVC, Kohlberg Kravis Roberts, Blackstone and Texas Pacific - has until that date to make an offer or withdraw its plans.
Last month, the group admitted it was considering the possibility of making a bid for Sainsbury’s.
The deadline was issued by the takeover panel after a plea from Sainsbury’s advisers.
Other companies have also been touted as possible bidders for Sainsbury’s since bid speculation began earlier this year.
Marks & Spencer said last week it had considered bidding but had now decided against any move. But it did concede it might bid if another party attempted a takeover.
Analysts estimate a deal for the UK’s fourth largest supermarket could be worth as much as £10bn.
Sainsbury’s has so far refused to comment on takeover speculation and analysts widely expect the company’s board to resist any offer.