The Israelis and Syrians have held secret talks about a peace deal, a former Israeli diplomat has said.
Assad raised the possibility of talks last October
Dr Alon Liel said the meetings were arranged in a private capacity, and Israeli sources said the talks were not officially sanctioned by Israel.
Israel's Haaretz daily says a series of agreements were reached, including an Israeli withdrawal from the Golan Heights, captured from Syria in 1967.
But the talks apparently collapsed with Israel's war in Lebanon last year.
According to the paper, Israeli and Syrian representatives met secretly in Europe several times between September 2004 and July 2006.
In exchange for a full Israeli pull-out from Golan Heights, captured in the Six Day War 30 years ago, Syria would end support for anti-Israel militant groups.
But Dr Liel stressed to the BBC that the representatives were operating privately and were not aiming at a final agreement, but a framework.
While Israel says that non-government representatives from the two countries may have met, Syria denies any secret meetings took place.
Official peace talks between Syria and Israel broke down six years ago.
But last October, Syrian President Bashar al-Assad said Damascus would be prepared to hold talks with Israel.
He acknowledged Syria and Israel could live side-by-side in peace accepting each other's existence.
Israel's deputy prime minister Shimon Peres also said Syrian representatives would be welcome to come to Jerusalem for talks.
But Israeli Prime Minister Ehud Olmert distanced himself from Mr Peres's remarks. The invitation, his spokesman said, was not issued on his behalf.
Israel and Syria have been officially in a state of war ever since Israel was established nearly 60 years ago.
Since 1967, Israel has occupied a part of Syrian territory, the strategically important Golan Heights, overlooking the Sea of Galilee.