Raj Chatha has become acting non-executive chairman with immediate effect, but it is believed board discussions on a permanent incumbent also began this week.
The Nisa Members Association (NMA) has called on its members to inform the board of their views by completing a survey on what they want to see from the new chairman.
NMA treasurer Ian Hunt, of Filco Foods, said that the association wanted any appointment to come from outside the current board structure.
He told Convenience Store: "We've now had three chairmen in the past six months. The NMA wants to make sure the right person is selected this time. We strongly believe we need a figure with a proven track record and that they should not come from within the company. The Nisa family is made up of wholesalers, independent retailers and five different symbol groups. They are all coming from different angles and it is a job to hold it all together."
Commenting on Booth's departure, which stemmed from his company's decision to use its own central distribution facilities to supply chilled goods to stores, Hunt added that a new chairman would have to be 100% committed to Nisa and its central distribution.
Bedfordshire-based Nisa retailer Kishor Patel added: "This definitely shouldn't be a rushed decision. Nisa-Today's is actually trading very well. I don't think it would do any real harm if the new chairman came from within, but there should be a requirement to support the central distribution."
In a statement, Nisa-Today's said it did not wish to comment on the matter "ahead of proper board discussions taking place".