Sainsbury’s is in talks to buy convenience operator Nisa, a move which would significantly bolster its position against Tesco’s expected merger with Booker.

Nisa is reportedly poised to sign an exclusivity agreement with Sainsbury’s, which would temporarily bar the corner shop group from courting other buyers.

Nisa, which buys and distributes for more than 2,500 independently-owned stores in the UK, has been working on a potential sale since the announcement that Tesco planned to acquire rival wholesaler Booker.

The Co-operative Group is also known to be one of the potential buyers for the Nisa group, but ongoing talks have not yet led to an agreement and Sainsbury’s is now understood to be the frontrunner.

Supermarket retailers continue to look at ways to tap into a shift in shopping habits as consumers increasingly favour smaller shopping trips rather than weekly shops at larger supermarkets.

Earlier this year Tesco announced its desire to buy the wholesaler Booker, which owns the Londis, Budgens and Premier brands, for £3.7bn.