South Africa's maize stocks stood at 2.81 million tonnes in May compared to 3.74 million tonnes at the same time last year, official figures showed on Monday.
The stocks were up, however, compared to 2.64 million tonnes in carryover stocks in April at the end of the 2003/04 May-April marketing season.
Traders said last week they had expected stocks to rise since deliveries to silos normally pick up during the harvest at this time of year.
Maize exports during May were 49,000 tonnes versus 88,000 tonnes in May 2003, the South African Grain Information Service said.
Imports were 83,000 tonnes, all yellow maize, up from 22,000 tonnes in May last year, SAGIS added.
The bulk of the stocks are white maize at 2.0 million tonnes with only 808,000 tonnes of the yellow variety, mainly used for animal feed.
With lower stocks of yellow maize, South Africa has been importing large quantities of it 404,000 tonnes during the previous 2003/04 marketing year.
Last week the government said the 2003/04 maize crop, which is currently being harvested, was forecast to reach 7.81 million tonnes, down from 9.39 million tonnes in the previous season.