JOHANNESBURG (Reuters) - South African private sector activity rose marginally in April as an improvement in business confidence encouraged companies to expand purchasing activity and staffing levels, a survey showed on Monday.

The S&P Global South Africa Purchasing Managers' Index (PMI) rose to 50.3 in April from 48.4 in March, its highest reading since February. A reading above 50 shows growth.

Business sentiment was boosted by a drop in rolling power cuts in April and a softer reduction in new orders.

"Some of the headwinds that have held the private sector back recently showed signs of easing in April, with reduced load shedding (power cuts) and a lesser degree of supply-chain delays signalled," said Andrew Harker, economics director at S&P Global Market Intelligence.

Some companies predict an improvement in demand after the general elections on May 29, Harker added.

South Africa went through April without a single day of power cuts by state power utility Eskom.

Eskom said last month it would probably be able to limit rolling power cuts over the winter months as the outlook for its fleet of power stations had improved.

(Reporting by Bhargav Acharya; editing by Christina Fincher)