Since it was launched in May 2008, the Fresh For Less everyday low pricing initiative and added-value packs had boosted sales of produce through its central distribution depot.
"This is no mean feat when the multiples have also been rolling up their sleeves to win a greater share with an array of footfall-winning offers," said a Nisa-Today's spokesman.
As part of the initiative, more products have been introduced to Nisa's offer, including 1kg value packs of apples, which are sold under Nisa's own label, Heritage.
Typically, between 10 and 12 fruit and vegetable lines feature in the promotional leaflets offered to
retailers with supporting point-of-sale material.
The timing of the launch last year was particularly opportune, said the spokesman. "The economy was beginning to nosedive and consumers have been looking for value for money on everyday essentials ever since," he said.
Fresh For Less had been "excellent", said Andrew Morris, produce manager at Stan's Superstore in Oswestry. "It has helped us to more than hold our own in what has been a volatile market," he said.
Nisa also announced that its retailers had raised more than £1m in the first year of its charity Making A Difference - Locally.
The scheme, also launched in May 2008, allows Nisa-Today's and Costcutter retailers to raise money through the sale of various products, with a percentage of the sale
going to local good causes.