American asset management fund Carlyle Strategic Partners is understood to be among a number of bidders for the Gaucho group.
Sky News reports that the company made a bid for Gaucho earlier this week.
It is understood that a number of bids have been made, with M Restaurants boss Martin Williams having previously said he was in discussions with the administrators.
The steak restaurant chain went into administration two weeks ago and closed 22 Cau branches with immediate effect, but 16 Gaucho restaurants continue to trade while a buyer is sought.
Administrators Deloitte said the Cau brand was "significantly loss-making" having suffered negative like-for-like sales for three years. Its collapse resulted in 540 redundancies.
Joint administrator Matt Smith said that in comparison the Gaucho brand "continues to trade well in its market segment, is profitable and has a strong underlying brand and guest loyalty".