Palestinian chief negotiator Saeb Erakat tendered his resignation on Saturday amid deadlock in efforts to renew peace talks with Israel, a Palestinian official said.
Erakat told AFP he was stepping down because of his responsibility for the disclosure of confidential documents on Al-Jazeera, shortly after his resignation was announced by senior PLO Yasser Abed Rabbo.
The chief negotiator said he was assuming "responsibility for the theft of documents from his office" that he said had been "deliberately" tampered with.
Last month, Erakat accused Al-Jazeera of taking part in a campaign to overthrow the Palestinian Authority (PA) after the Doha-based television began to release more than 1,600 confidential files known as "The Palestine Papers."
The documents, shared by Al-Jazeera and Britain's Guardian daily, expose concessions to Israel in 10 years of secret peace talks, embarrassing and angering the Palestinian leadership.
Erakat at the time accused Al-Jazeera of trying to discredit the peace process and provoke his people into "a revolution against their leaders in order to bring down the Palestinian political system."
He pointed to a possible US-Israeli effort to topple the PA because of its refusal to take part in US-brokered direct peace talks unless the Jewish state halts West Bank settlement construction.
The files allege that Palestinian negotiators offered unprecedented concessions during peace negotiations, including on the ultra-sensitive subjects of Jerusalem and refugees, with nothing in return from Israel.
They also show PA members closely cooperating with Israel in its fight against the Palestinian Islamist movement Hamas, Fatah's bitter rival which rules the Gaza Strip.
Hamas on Saturday welcomed Erakat's offer to resign.
The step "shows that the leaked documents were authentic," spokesman Fawzi Barhum told AFP, urging the Palestine Liberation Organisation to halt all negotiations with Israel.