Tiger Brands, which makes pasta, energy drinks and breakfast cereal, wrote off R105m of certain factory assets of Dangote Flour Mills following a review of their utilisation levels.
The impairment comes within a year of an R849m write-down of the same business, which suffered a 6.28 billion naira ($36.2m) pre-tax loss in August as it struggles with tough competition and weak margins.
Tiger Brands has been trying to turn profit from Dangote Flour Mills since paying nearly $200m for a controlling stake two years ago as part of broader plan to expand into rest of Africa to offset slow growth at home.
The Johannesburg-based company said Nigeria, where it competes with Nestle Nigeria, remains central to its expansion.
Tiger Brands also reported an 11% increase to R18.16 in headline earnings per share, helped partly by cost cuts at home, where debt-laden consumers are spending guardedly.