Aug 12 (Reuters) - South Africa’s Northam Platinum said on Wednesday it expects higher annual earnings, underpinned by higher metals prices and increased sales volumes.

Normalised headline earning per share (HEPS) for the full year ended on June 30 is expected to be in the range of 624.53 to 690.27 South African cents.

HEPS is the main profit measure used in South Africa and strips out certain one-off items. (Reporting by Samantha Machado in Bengaluru; Editing by Arun Koyyur)