BEIRUT – Syria said Monday it is prepared to hold talks with armed rebels bent on overthrowing President Bashar Assad, the clearest signal yet that the regime is growing increasingly nervous about its long-term prospects to hold onto power as opposition fighters make slow but persistent headway in the civil war.

Meanwhile, the umbrella group for Syrian opposition parties said it had reversed a decision to boycott a conference in Rome being held to help drum up financial and political support for the opposition. Walid al-Bunni, a spokesman for the Syrian National Coalition, said the move came after a phone call between the group’s leader, Mouaz al-Khatib, and U.S. Secretary of State John Kerry.

Al-Bunni told pan-Arab broadcaster Al-Arabiya the decision was made based on guarantees al-Khatib heard from western diplomats that the conference would be different this time. He did not elaborate. The boycott had put the group at odds with its Western backers.