Pre-tax profits at frozen food discounter Heron Foods fell to £7.05m last year, down from £7.77m, accounts at Companies House have revealed.

Accounts for the year to 25 December 2010 revealed the chain, which has 180 stores, closed a number of unprofitable stores and paid down debts over the period, including overdrafts and hire purchase agreements.

Sales rose 5% from £141m to £148m due to a capital expansion programme and increased numbers of customers looking for alternatives to major supermarkets during the recession.

The directors said they were "optimistic" about the future, adding that Heron planned to move ­existing stores to more ­favourable locations wherever possible and to open new stores as soon as locations became available.

Heron said it would also continue to invest to maximise return from its stores and that it expected a new distribution facility to help drive cost out of the business. "Significant" cost savings could also be made through the introduction of more energy-efficient technology in its stores.

Last month, rival frozen discounter Farmfoods ­reported a 20% increase in sales to £578.8m for the year ending December 2010. Its pre-tax profits jumped 30% to £17m.