LONDON (Reuters) - British supermarket operator Sainsbury (>> J Sainsbury plc) has been given more time to make a firm bid for Argos-owner Home Retail (>> Home Retail Group Plc), after a possible higher rival offer from South African group Steinhoff International (>> Steinhoff International Holdings NV) emerged on Friday.

Home Retail said on Monday the Takeover Panel watchdog had extended Tuesday's deadline for Sainsbury to formalise its takeover proposal to March 18, the same date as for Steinhoff to make a firm bid or walk away.

Frankfurt-listed Steinhoff, which already has a retail presence in the UK through Bensons Beds and the Harvey's furniture chain, on Friday proposed an all-cash offer of 175 pence for each Home Retail share.

That was 8.5 percent higher than Sainsbury's cash and shares approach, worth 161.3 pence or a total of 1.3 billion pounds when it was made on Feb. 2, and Home Retail had said it was willing to recommend.

Shares in Home Retail have jumped nearly three quarters since news of a possible bid from Sainsbury emerged on Jan. 5.

They closed up 13 percent at 173.4p on Monday as Steinhoff's announcement on Friday came after the stock market closed. Sainsbury shares closed down 2.3 percent at 255.65p, valuing its proposal at about 165p.

Sainsbury Chief Executive Mike Coupe wants Argos to accelerate the supermarket's growth strategy. By creating Britain's largest general merchandise business it would be less reliant on a food market showing little growth.

Argos's sales and delivery network, one of the most advanced in Britain, is also attractive.

Steinhoff's move had surprised analysts, who had previously said it would be hard for any rival to unlock the 120 million pounds of annual savings and benefits Sainsbury identified the deal would deliver in three years.

Coupe has repeatedly said Sainsbury will not overpay for Home Retail. But walking away would create its own problems.

"Sainsbury’s has effectively questioned the rationale of a 'standalone food retailer' and it needed this extra non-food capability to strive," said Bernstein analyst Bruno Monteyne.

"Pulling away from the deal would leave an important strategic question mark of how they plan to fill that gap."

Monteyne expects Sainsbury to match Steinhoff's proposal but noted any bid above 186p would likely require shareholder approval, adding further complexity.

Steinhoff, which has operations in Britain, continental Europe, southern Africa and the Pacific Rim, has a market value of about 18 billion euros (£14 billion), more than double that of Sainsbury. It is yet to set out what its strategy for Argos would be, or what cost savings it could achieve.

(Editing by Sarah Young and David Holmes)

By James Davey