Palestinian President Mahmoud Abbas and Hamas' exiled leader, Khaled Mashaal, spoke to each other for the first time in months on Thursday, in what officials said was a sign that the rivals are close to forming a coalition government. The renewed talks also signaled that Hamas may be hesitant to act on its threat to resume attacks on Israel following this week's deadly Israeli artillery barrage in the northern Gaza Strip. Abbas, a moderate, has been trying to persuade the radical Islamic group, which controls the Palestinian legislature and Cabinet, to form a unity government with his Fatah party. He hopes the deal will force Hamas to moderate its anti-Israel ideology and help end an international boycott against the Palestinian government. Talks have been dragging on for months, delayed in large part by animosity between the two men. Abbas cut off contact with Mashaal last spring after the Hamas leader criticized Abbas in a speech. Abbas called Mashaal, who lives in Syria, at the urging of advisers who realized that progress couldn't be made without dealing with the Hamas leader, officials said. "The phone call reflects the positive spirit prevailing in Gaza in an attempt to reach formation of a new unity government," said Nabil Abu Rdeneh, a top presidential aide. "We hope to be able to realize progress very fast." Despite the upbeat forecast, repeated attempts to forge a unity government have faltered in recent months. Mashaal has balked at Abbas' insistence that the government recognize Israel's right to exist - a key condition for lifting the international boycott against the Palestinian Authority. Abbas has been in Gaza this week to negotiate with leaders of the Hamas-led government. Prime Minister Ismail Haniyeh suspended the talks on Wednesday to protest an errant Israeli artillery attack that killed 18 Palestinian civilians. But the talks quickly resumed. At a news conference, Mashaal angrily called off a February 2005 truce with Israel and called for a resumption of attacks. However, Hamas would be taking a major risk by resuming violence. Renewed attacks would further hurt efforts by the group, already battered by international sanctions, to win international legitimacy.