The Co-op is close to making an offer for member-owned wholesaler and convenience store group Nisa.

Following a number of “positive discussions” in recent weeks, Nisa chairman Peter Hartley said the Co-op was keen to progress as quickly as possible, in the hope that a transaction could be finalised.

As a result, the Nisa board has granted the Co-op a period of exclusive due diligence from today.

In a letter to Nisa members, Hartley said: “Subject to the results of the due diligence, it is anticipated that the Co-op could be in a position to make a final offer to the members for your consideration.

“Should an offer of merit emerge from this process, it will be for you, the members, to decide on whether to accept it.”

He added that there was no guarantee that an offer would be forthcoming.

“Key elements of the discussion remain ongoing and while these are not yet resolved the conversations with the Co-op to date have been pragmatic and constructive,” he said.

Nisa had previously caught the interest of Sainsbury’s but its exclusive talks were ended amid competition concerns.