HARARE (Reuters) - Zimbabwe's electoral commission will announce the date of the country's presidential runoff election by the end of Friday, state television reported on Thursday.

The commission said on Wednesday the presidential run-off could be delayed until the end of July -- four months after the disputed March 29 elections.

Official results showed that opposition leader Morgan Tsvangirai beat President Robert Mugabe in the election but not by enough votes to avoid a run-off.