By Robert Evans GENEVA, Nov 14 (Reuters) - An agreement to start expert talks on cluster bombs next year is an important step forward, disarmament negotiators said on Wednesday. Envoys from Europe and Latin America told a news conference this week's accord -- described as half-hearted by campaigning bodies -- showed some big powers opposed to a total ban on the bombs accepted that something had to be done. "We think that by agreeing on a negotiating mandate, we have reached a breakthrough," said Greek ambassador Franciscos Verros, who chaired a five-day review of a 1981 pact on especially dangerous conventional weapons. The review meeting, said Brazil's Carlos da Rocha Paranhos, was a "positive step forward" and had put the issue of an eventual protocol on limiting the use of cluster bombs on to the agenda for the United Nations-sponsored talks. But the agreement fell far short of setting formal negotiations for a ban on the weapons that many countries and humanitarian bodies want. Cluster bombs eject thousands of bomblets over a wide area, many of which remain unexploded for years. They kill or maim thousands of non-combatants in war or frontier zones every year. The Swiss-based International Committee of the Red Cross (ICRC) said it was regrettable that the mandate for the expert talks showed no commitment to working for a legally binding pact prohibiting cluster bombs. The U.S. Campaign to Ban Landmines said nations who signed the 1981 accord (CCW) had "again failed to deliver on cluster weapons". Some 70 countries support a total ban and are taking part in a parallel process launched in Oslo in February aimed at negotiating a pact by the end of 2008. They meet next in Vienna from December 4 to 7. The supporters of that process hope it will follow the example of a movement outside formal international disarmament talks in the early 1990s that led to a 1997 treaty banning production and use of landmines, now signed by 155 states. Resistance to a ban on cluster munitions comes from countries including the United States, Russia, China, India and Pakistan. But they agreed this week to starting the experts' process to look at how its humanitarian impact can be minimised. A statement from the United States -- which like other opponents of a ban is staying aloof from the Oslo process -- said the agreement to start the expert talks affirmed the importance of the CCW in discussions on cluster weapons. As the only framework bringing together the users and producers of munitions and those concerned with their humanitarian impact, it said, the CCW alone could produce results and "real humanitarian progress". (Editing by Robert Woodward)