A Panera Bread Company restaurant in the St. Louis area where patrons for eight years had the option of paying as much or little as they wanted for a meal is closing its doors.

Panera founder and Executive Chairman Ron Shaich told the St. Louis Post-Dispatch that the St. Louis Bread Co. Cares Community Cafe in Clayton, Missouri, is imminently due to close because it was on a month-to-month lease and the store would have required a big investment.

St. Louis Bread Co. is part of St. Louis-based Panera, which operates more than 2,000 bakery-cafes.

Loaves of bread sits on a table at St. Louis Bread Co. Cares Community Cafe, part of Panera, in Clayton - the restaurant is closing its doors for good on Tuesday 9 January (File photo)

'The nature of the economics did not make sense,' Shaich said.

The cafe opened in 2010 in an existing Panera-run restaurant blocks from the St. Louis County government buildings.

The idea for the Clayton cafe was to encourage people who could afford to pay the suggested price or more to do so, in effect subsidizing those who were more financially stretched.

Shaich told the Post-Dispatch that in the seven years since, about 500,000 meals were served through this cafe, 'all at no set prices, as a gift to the community'.

He said customers paid, on average, about 85 percent of the suggested price, proving, he said, 'that people are fundamentally good'.

'We loved it, it worked well, it proved that the idea would work,' Shaich said.

The company opened similar cafes in Chicago, Dearborn, Michigan, Portland, Oregon and Boston. Now only the Boston location remains open.

Shaich stepped down as CEO of Panera on 1 January.

Panera was acquired by the Luxembourg-based JAB Holding Co., which also owns Krispy Kreme, Caribou Coffee and other entities, in July.