London-listed Petra Diamonds said on Thursday that its electricity use restrictions have been lifted by South Africa's State utility Eskom and its mines are operating at normal load levels.
The company restarted its Cullinan, Finsch and Koffiefontein mines in South Africa on Tuesday, but added that it was restricting power use in line with requirements by Eskom.
Rolling blackouts in South Africa are set to continue on Thursday as some generating units are still down, after a week of heavy rains across parts of the country caused flooding, aggravating problems at struggling power firm Eskom.
Shares in Petra Diamonds were 1.4% higher at 8.2p at 12:11 GMT.