The PLO Executive Committee accepted the document, authorizing Abbas to call a referendum on it, said Yasser Abed Rabbo, a senior Palestinian official.
Abbas' deadline expired Tuesday, but he gave the militant Islamic group more time due to pressure from other officials.
Meanwhile, Israeli Prime Minister Ehud Olmert will meet King Abdullah II in Jordan, his second trip to an Arab country since taking office in May, and his second meeting with an Arab head of state this week. Olmert held talks with Egyptian President Hosni Mubarak in Sharm el-Sheik, Egypt, on Sunday.
The leaders are discussing how to revive the peace process, now that the Islamic militant group Hamas controls the Palestinian Authority, reports . Jordan and Egypt are urging Olmert to bypass Hamas, and negotiate with moderate Palestinian president Mahmoud Abbas.
On Monday, Abbas ruled out any changes in the 18-point document negotiated by Palestinian prisoners in an Israeli lockup. It accepts a Palestinian state in the West Bank, Gaza Strip and east Jerusalem, implying recognition of Israel next to it.
The plan was formulated by politically powerful Hamas and Fatah prisoners. But the Islamic group's exiled leaders, who make final decisions on policy, have refused to accept the document.
Hamas spokesman Sami Abu Zuhri insisted that the talks must continue, saying parts of the document are positive, but Hamas has problems with other parts.
"You cannot raise the sword of ultimatum, you cannot raise the issue of a referendum while you are talking about dialogue," he told reporters in Gaza. He said calling a referendum meant circumventing the elected government.
Hamas lawmaker Khalil al-Hiyah said that despite Abbas' statement, there was still time to resume the talks instead of calling a referendum.
A vote could deeply embarrass Hamas. Polls show the prisoners' document would win broad approval. Hamas won January elections in a landslide against Abbas' Fatah, but government inefficiency and corruption were the main issues, not policy toward Israel.
Hamas opposes the existence of a Jewish state in an Islamic Middle East and has rebuffed Western demands to recognize Israel, accept previous peace accords and renounce violence. The West cut off aid to the Hamas-led government, leading to a financial crisis.
Abbas has endorsed the prisoners' plan as a way to end the crushing Western sanctions and allow him to resume peace talks with Israel.
Israeli Foreign Minister Tzipi Livni said Monday that the document is an internal Palestinian issue, and Israel is not commenting on it.