Kumba, a unit of Anglo American, said headline earnings per share (EPS) totalled 11.8 rand in the year to end December compared with 34.3 rand a year earlier.
Headline EPS is the main gauge of profit in South Africa and strips out certain one-off items.
Iron ore prices fell about 35 percent in 2015 due to a supply glut and growth concerns in top consumer China, forcing Kumba to cut jobs and restructure its main mine, Sishen.