Gourmet Burger Kitchen (GBK) saw operating losses grow in the year to 24 February 2019, despite remedial actions boosting like-for-like sales later in the period.
Its South African-based owner, Famous Brands, reported that GBK had seen an operating loss before non-operational items of £4.6m, compared to £3.6m the previous year.
Total sales declined by 7% in the period, with like-for-like sales down by 4.3%.
However remedial actions taken following the group's Company Voluntary Agreement, which was completed in December and saw the closure of 24 sites, saw like-for-like sales grow by 8.1% in the 12 weeks following year-end.
Famous Brands said: "Management is optimistic that remedial actions underway to ensure the long-term sustainability of the business are gaining momentum."
The company also owns Wimpy UK, and reported that 12 restaurants were closed in the year with the portfolio now standing at 67.
Despite consolidation of the estate like-for-like sales grew by 5.5% and operating profits grew by 16% to R18m (£958,860).