Little Chef has put 38 of its restaurants up for sale with a combined price tag of about £10.5m.
The properties, which stretch from Perthsire in Scotland to Whitstable in Kent, are being offered as single units, groups or a whole package.
A Little Chef spokesman said the company was "considering the future of 38 of its businesses across the UK".
It added that the move was part of a "valuation review".
It has placed them on the open market to find out how much they are worth and will decide whether or not to sell based on the response.
The public sale comes after the company is understood to have made several recent private disposals.
The spokesman added that if any of the restaurants are sold or closed it would try to find suitable employment for the staff.
The auction is being handled by agents Christie & Co, which has set a deadline for bids of 22 October.
On the market are two sites in Scotland, one in Yorkshire, four in Wales, two in the West Country, 21 in the Midlands and eight in London and the South-east.
Prices range from £45,000 for a leasehold site in Shropshire, to a freehold restaurant in Newark, Nottinghamshire, which is expected to fetch £650,000. The average price tag is £250,000-£300,000.
Little Chef has more than 350 outlets across the UK.
by Tom Bill