A Zimbabwean court has decided to drop treason charges against Tendai Biti, a top opposition leader.

The move on Friday came after state lawyers failed to provide a trial date for the secretary-general of the opposition Movement for Democratic Change (MDC).

The decision of the court underlined Zimbabwean government's eagerness to improve relations with the opposition, ahead of the formation of a unity government.

However, Olivia Mariga, the magistrate, said on Friday that the prosecution could bring the case back to court by issuing fresh summons.

"The magistrate refused to remand Biti, and accepted our argument that the state had broken its own undertakings to the court to proceed to facilitate a speedy trial," Lewis Uriri, Biti's lawyer, said.

Biti was charged with seeking to oust Robert Mugabe, the Zimbabwe president, unconstitutionally by saying Morgan Tsvangirai, the MDC leader, had won a March 2008 poll against Mugabe outright.

Biti, who led the MDC's team in negotiating a unity government with Mugabe's Zanu-PF, says the charges were trumped up.

Unity government

The court reprieve for Biti is likely to ease tensions between Zanu-PF and the MDC after months of political unrest which has contributed to the country's continued economic dilapidation.

On Thursday, the parliament passed a constitutional bill to allow the establishment of a coalition government under a power sharing deal signed in September.

The MDC agreed to join the unity government last week, a move previously held up by arguments over the division of power in government.

Zanu-PF and the MDC have been jostling to finalise the unity government since last year's disputed run-off vote, which Tsvangirai boycotted due to citied violence against his supporters.