Nisa named non-executive director Arnu Misra as interim chief executive as it unveiled an uplift in sales during its first half.
As previously reported, Read stepped down at the end of September after almost three years at the helm of the retailer and wholesaler.
Read was credited with returning Nisa to profit in July last year, when it reported an EBITDA of £7.3m.
That figure increased to £8.6m this year, as pre-tax profit reached £2.8m.
In its latest trading update, covering the 26 weeks to October 1, Nisa said total sales spiked 12.4% to £728m.
The company’s core convenience chain registered a 1.9% uplift in like-for-like sales, driven by strong growth in new stores and member recruitment.
Nisa said it opened a net new 284 stores during the half, compared with a net loss of 110 stores during the same period last year.
Non-tobacco sales rose 0.8% on a like-for-like basis, while tobacco sales fell 2.7%.
However, Nisa insisted that was still a better performance than in the wider market.
Nisa chairman Peter Hartley said: “I am pleased to report strong trading in the first six months of the year. We have continued to serve our existing members well, and as a result new member recruitment has shown significant gains.
“We are delighted to have Arnu as interim CEO. He has a wealth of retail experience and is ideally placed to lead Nisa as we seek to optimise the service, benefits and opportunities we can bring our members.”
Misra added: “I am pleased to be leading Nisa at a time of great change for the convenience sector as top-up shopping continues to increase.
“I have spent many years working in the retail industry and am looking forward to drawing on this experience to provide Nisa members with an exceptional value proposition that delivers for their customers.”