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GAZA, July 4 (Reuters) - Alan Johnston, the BBC journalist held hostage in the Gaza Strip since March, was handed over by his Islamist captors to ruling Hamas officials on Wednesday, Palestinian sources close to negotiations for his release said.

The sources told Reuters they saw the 45-year-old Briton being taken into the care of officials from the Hamas movement, which seized full control of Gaza three weeks ago.

"He is sitting with his colleagues from the BBC office in Gaza," one of the witnesses said. "He is talking to them and he looks fine and well".

Johnston, the only Western correspondent working full-time in the troubled coastal enclave, went missing on March 12.

His captors later declared themselves to be the Army of Islam, an al Qaeda-inspired group with links to one of Gaza's powerful clans.

They issued Web videos showing Johnston and seeking the release of Islamists held prisoner by Britain and other states.

Most recently, after Hamas officials threatened to free him by force from the clan's stronghold, Johnston was shown wearing a suicide belt with the warning he would die if that happened.

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