Zambian opposition leader Michael Sata was holding on to his lead over incumbent Rupiah Banda as counting moved beyond a halfway point in the race to become the next president of Africa's biggest copper producer, the Election Commission said.

According to the latest tally read out at the Commission's headquarters, Sata had 639,787 votes compared with 542,362 for Banda. The figures were based on results from 85 of the country's 150 constituencies.

(Reporting by Chris Mfula; Editing by Ed Cropley)