Sigma Pharmaceuticals’ shares fell 7.7% to A$0.48 on Monday following the sale of its drugs unit to South African drug manufacturer Aspen Pharmacare.

The Australian drug manufacturer sold the unit, responsible for producing generic medicines and treatments for rare diseases, for A$900m ($810m), resulting in its largest share-price fall since July.

Credit Suisse Group AG have suggested that short-term earnings growth in Sigma’s remaining business is likely to be muted, according to Bloomberg.