(Reuters) - OPEC began negotiations on Monday for a new production deal aimed at healing the rift caused by a bad-tempered failure to agree an output target when it last met in June.

At stake for the Organization of the Petroleum Exporting Countries at a Wednesday meeting is a cohesive and credible output policy heading into a year when a sluggish global economy could undermine fuel demand and cut oil prices that are now above $107 a barrel.

I think they have to agree this time because they need to be credible, said former Algerian Oil Minister Chakib Khelil.

If OPEC finds itself battling a potential price collapse next year, said Washington consultancy PFC, establishing the basis for this cohesion will be OPEC's first order of business.

Without a collective supply target, OPEC members with spare capacity - Saudi Arabia and its Gulf Arab allies - remain free to pump at will.

Signs are that a deal is likely.

A sherpa meeting of OPEC experts on Monday discussed a report from OPEC headquarters that forecasts demand for OPEC crude at 30 million bpd, near current output, in the first half of 2012.

I think there's a gentleman's agreement. The ongoing production won't be increased or decreased, an Iranian delegate told Reuters after the experts' meeting.

30 million is the number we're looking at, yes, said a Gulf Arab OPEC delegate.

Leading producer Saudi Arabia has made clear its intention to keep oil prices under control, saying last week it was producing a surprisingly high 10 million barrels daily of crude, much more than estimated by most in the oil industry.

That pleased consumer nations worried about the impact of oil prices on global growth.

OECD stock levels are at historically low levels, plus we are in very fragile economic recovery situation, said Fatih Birol, chief economist at the International Energy Agency.

The Saudi position has worried price hawks in OPEC like Iran, Algeria and Venezuela who want to keep oil above $100.

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Graphics: Demand for OPEC crude: link.reuters.com/zyk55s

OECD inventories fall: link.reuters.com/cyk55s

OPEC export revenues: link.reuters.com/wyk55s

OPEC market share link.reuters.com/xem55s

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Iran is expected to seek a commitment from Saudi Arabia to cut back to accommodate the restoration of Libyan supply.

Should OPEC's present output continue, with the increased production of Libya and Iraq next year we would witness an increase in stockpiling and a drop in crude oil prices, said Iran's OPEC representative Mohammad Ali Khatibi.

As holder of OPEC's rotating presidency, Tehran looks willing to compromise on an output target so as not to end the year with a second failed meeting under its chairmanship. Iran's new oil minister Rostam Qasemi told Reuters last week that producers should follow the technical guidance from OPEC's Vienna secretariat.

The secretariat's forecast includes an allowance for stocks to rebuild in the second quarter when global fuel demand is at its lowest. Inventories among OECD countries currently are at about 55 days of forward demand compared to 61 days in the spring.

Not allowing for stock changes, the secretariat puts demand for OPEC crude at 29.9 million bpd in the first quarter and 28.7 million bpd in the second quarter.