Musgrave Group is cutting staff and imposing a pay freeze to help it cope with what it describes as "very tough" trading conditions in the Irish market.

The cutbacks, which include 20 compulsory redundancies, will be confined to operations in the Republic, where its SuperValu, Centra and Daybreak franchises account for about a fifth of the grocery sector.

"Higher-paid staff" will be asked to accept a wage freeze until the end of the year and Musgrave, which employs 2,800 people, will not be renewing the contracts of temporary workers. The company was unable to say how many temporary workers would lose their jobs or what terms would be offered to the staff being made redundant. Musgrave spokeswoman Edel Clancy described trading as "very tough, among the toughest this group has faced".

The cutbacks come as figures from the Central Statistics Office show Irish retail sales plummeted 20% in January, the biggest fall since records began almost 50 years ago. The slump has been compounded by consumers shopping in Northern Ireland, where prices can be more than 30% cheaper due to lower VAT and the fall in sterling. According to the CSO, the cost to the Republic's retailers of the exodus will be €700m this year.

This behaviour was a factor in Musgrave's difficulties, admitted Clancy. "If you have 200,000 families from here shopping in Northern Ireland then that is bound to have an impact," she said.

However, she added that Musgrave was investing in price cuts in its SuperValu outlets and was "encouraged by the response".

Musgrave's UK operation, which includes the Budgens and Londis symbol groups, has not been affected.

Meanwhile, Select Retail Holdings, which bought the Superquinn chain four years ago, is reported to be in talks with bankers on rescheduling repayments over a longer period. The retailer recently blamed the loss of business to Northern Ireland for the closure of its store in the border town of Dundalk.