SHOP owners are demanding an urgent meeting with competition authorities amid fears they could be forced out of business by big supermarket chains.

The Association of Convenience Stores (ACS) is calling for a meeting with the Office of Fair Trading after Sainsbury's acquired 114 convenience stores run by Jacksons Stores yesterday, in a deal thought to be worth £100m.

The call came as Mills Group, which has 84 outlets across the North-East, was identified as a potential target in the sector.

The ACS fears supermarkets will use their size to sell products at below wholesale prices and is pressing for a ban on the tactic.

ACS also wants transparency of buying prices amid concerns that supermarkets can negotiate better terms with suppliers than smaller retailers.

David Rae, chief executive of ACS, said the implications of the latest deal involving Sainsbury's would be felt widely and acutely in the grocery sector.

Safeguards should be introduced to establish a more level playing field in the grocery market, possibly via a strengthened supermarket code of practice, he said.

"Otherwise, the Government will be forced to legislate when choice and diversity have all but disappeared," Mr Rae said.

Interest among supermarkets in the convenience store sector has grown during the past 12 months as chains struggle to gain permission for larger outlets.

The market is viewed as a major growth area and is thought to be worth about £23bn a year.

The deal for Jacksons Stores, which owns shops across Yorkshire and the North Midlands, was the second significant move made by Sainsbury's into the convenience store sector this year.

In February, it bought Bells Stores for about £22m.