By Nidal al-Mughrabi

GAZA (Reuters) - A hunger-striking Palestinian prisoner was exiled by Israel to the Hamas-ruled Gaza Strip on Sunday, Palestinian officials said.

The deal involving Ayman Sharawneh, whose case had helped fuel Palestinian protests, could reduce friction ahead of Wednesday's two-day visit by U.S. President Barack Obama to Israel and Palestinian territory.

Sharawneh, 37, from the Hebron area in the occupied West Bank, had signed an agreement to stay in Gaza for 10 years, according to Qadura Fares, head of an advocacy group for Palestinian prisoners.

Israel made no comment.

Sharawneh had been freed from an Israeli prison as part of a 2011 swap for an Israeli soldier who was held for more than five years in Gaza, then arrested again last year.

He had joined other prisoners in intermittently refusing food in protest against their being jailed without trial.

Sharawneh, who had been treated in Israeli hospitals during his hunger strikes, was driven into Gaza in an ambulance through the high-security Erez Crossing under cover of darkness.

He was admitted to the main hospital in Gaza City, where he received a hero's welcome - dozens of supporters greeting him with green and white Hamas flags.

A pro-Hamas prisoners' association said Sharawneh was being admitted to an intensive care unit.

Ismail Haniyeh, prime minister of the Hamas government, praised Sharawneh as a "hero prisoner."

He had originally been jailed in 2002 during a Palestinian uprising. After his rearrest, he was among four prisoners who began hunger strikes in protest.

The condition of those inmates and the death of another detainee helped fuel a string of protests in which dozens were injured across the West Bank. Two of the other inmates have since stopped their hunger strikes after a promise to free them.

Both sides have sought to calm the atmosphere ahead of what will be Obama's first visit as president, for talks expected to address peace negotiations frozen since late 2010 after disputes over Jewish settlement building.

Israel holds 178 Palestinians as "administrative" detainees - jailed without trial as suspected militants for renewable three to six-month terms based on classified evidence.

Qadoura stressed that Shawarneh had signed onto the deal of his own accord. Palestinian authorities object to deportations from land they seek for a state.

(Editing by Matthew Tostevin)