JOHANNESBURG (Reuters) -South Africa's Pepkor Holdings reported a 3.1% fall in half-year earnings on Tuesday citing ongoing supply chain disruptions at local ports impacting the discount retailer's merchandise imports.

The backlogs at ports stem from factors including adverse weather and under-investment in equipment and maintenance, according to South African state-owned logistics company Transnet.

"Logistics teams are making good progress in flexing the group's distribution capability to deal with supply backlogs, prioritising stock freshness to minimise the risk of markdowns," the clothing and electronics retailer said.

The owner of PEP and Ackermans clothing brands said headline earnings per share (HEPS) fell to 75 cents in the half-year ended March 31 from 77.4 cents a year earlier.

Normalised HEPS, which exclude certain non-recurring items, however, grew by 7.8%.

Revenue rose by 9.5% to 43.3 billion rand ($2.36 billion) with sales growth strengthening in the second quarter buoyed by back-to-school sales and strong Easter trade. PEP, Ackermans and Pepkor's Speciality businesses all posted double-digit sales growth.

Retail gross profit margins increased by 200 basis points to 38.1%, benefiting from improved full-price sales with lower mark down activity at PEP and Ackermans. Lower shipping costs at PEP also helped.

($1 = 18.3645 rand)

(Reporting by Nqobile Dludla; editing by Tom Hogue and Jason Neely)