Bidders for Bay Restaurants have been given a deadline of the end of July for full and final offer for the business.
The sale, which is being handled by boutique advisory McQueen, has attracted interest from a mixture of trade and private equity buyers.
It is understood that some bidders are looking to buy the whole business while others are focused on either the La Tasca tapas chain or Ha Ha Bar & Grill.
A source said: "The sale process has reached stage two with bidders now sent letters setting a deadline for offers.
"There's been a good level of interest in the business and bidders now have five weeks to finalise offers."
Bay Restaurants is made up of the 73-strong La Tasca and 24 Ha Ha venues.
The Slug & Lettuce brand was transferred out of Bay Restaurants at the end of February and is now part of sister company Town & City Pubs.
Bay chief executive Paul Symonds chief executive left the business at the time and it is now headed by Suzanne Baker, the former Wetherspoon commercial director.
It was originally created by Robert Tchenguiz but his involvement ceased in March 2009 in the wake of moves by his lead bank Kaupthing to recall hundreds of millions of pounds of loans. Both Bay and Town & City are chaired by Ian Payne.
Analysts estimate the business could be worth £100m.
Bay Restaurants and Town & City Pubs were formed out of the pre-pack administration of Laurel Pub Company, which itself was created out of three businesses — Laurel Pub Company, SFI Group and Yates.