By Nidal al-Mughrabi

GAZA (Reuters) - Alan Johnston, the BBC journalist held hostage in Gaza, was freed early on Wednesday after a late-night deal between the ruling Hamas Islamists and the al Qaeda-inspired clan group that kidnapped him in March.

"It is just the most fantastic thing to be free. It was an appalling experience," he told the British public broadcaster from the home of local Hamas leader Ismail Haniyeh after his 114-day ordeal at the hands of the shadowy Army of Islam.

Haniyeh, whose movement routed the forces of the secular, Western-backed Palestinian president last month to seize full control of the enclave, said the outcome "confirms (Hamas) is serious in imposing security and stability and maintaining law and order in this very dear part of our homeland."

Khaled Meshaal, Hamas's overall leader in exile, hailed the success and told Reuters it contrasted with "anarchy" that prevailed when the Fatah faction of West Bank-based President Mahmoud Abbas was operating in the Gaza Strip.

Johnston, the only Western correspondent based full-time in the troubled Gaza Strip, said he sensed his captors felt new pressure once Hamas seized control in fighting three weeks ago.

Negotiators, who were backed up by Hamas fighters cordoning off the Gaza City stronghold of the kidnappers, said the final deal was clinched by a senior Muslim cleric issuing a fatwa, or religious edict, for Johnston's release.

No ransom was paid nor other conditions attached. The group had previously demanded Britain and other states free prisoners.

"I dreamt many times of being free and always woke up back in that room. Now it really is over and it is indescribably good to be out," said Johnston, a Scot who turned 45 in captivity.